From 713947e72139b353b94e1637d1839f1566ffa971 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E7=8E=8B=E5=8A=B2=E9=B9=8F?= Date: Tue, 14 Jan 2020 19:06:08 +0800 Subject: [PATCH] h&v scroll view enhancement --- .../java/pub/doric/shader/ScrollerNode.java | 10 +- .../java/pub/doric/widget/HVScrollView2.java | 1565 +++++++++++++++++ 2 files changed, 1570 insertions(+), 5 deletions(-) create mode 100644 doric-android/doric/src/main/java/pub/doric/widget/HVScrollView2.java diff --git a/doric-android/doric/src/main/java/pub/doric/shader/ScrollerNode.java b/doric-android/doric/src/main/java/pub/doric/shader/ScrollerNode.java index 18ccf135..e343aff6 100644 --- a/doric-android/doric/src/main/java/pub/doric/shader/ScrollerNode.java +++ b/doric-android/doric/src/main/java/pub/doric/shader/ScrollerNode.java @@ -21,7 +21,7 @@ import com.github.pengfeizhou.jscore.JSValue; import pub.doric.DoricContext; import pub.doric.extension.bridge.DoricPlugin; -import pub.doric.widget.HVScrollView; +import pub.doric.widget.HVScrollView2; /** * @Description: pub.doric.shader @@ -29,7 +29,7 @@ import pub.doric.widget.HVScrollView; * @CreateDate: 2019-11-18 */ @DoricPlugin(name = "Scroller") -public class ScrollerNode extends SuperNode { +public class ScrollerNode extends SuperNode { private String mChildViewId; private ViewNode mChildNode; @@ -50,12 +50,12 @@ public class ScrollerNode extends SuperNode { } @Override - protected HVScrollView build() { - return new HVScrollView(getContext()); + protected HVScrollView2 build() { + return new HVScrollView2(getContext()); } @Override - protected void blend(HVScrollView view, String name, JSValue prop) { + protected void blend(HVScrollView2 view, String name, JSValue prop) { if ("content".equals(name)) { mChildViewId = prop.asString().value(); } else { diff --git a/doric-android/doric/src/main/java/pub/doric/widget/HVScrollView2.java b/doric-android/doric/src/main/java/pub/doric/widget/HVScrollView2.java new file mode 100644 index 00000000..fa1df393 --- /dev/null +++ b/doric-android/doric/src/main/java/pub/doric/widget/HVScrollView2.java @@ -0,0 +1,1565 @@ +/* + * Integration of ScrollView and HorizontalScrollView + * + * For some unknown reason, the H/V scroll bar are missing. + */ + +package pub.doric.widget; + +import android.content.Context; +import android.graphics.Rect; +import android.util.AttributeSet; +import android.view.FocusFinder; +import android.view.KeyEvent; +import android.view.MotionEvent; +import android.view.VelocityTracker; +import android.view.View; +import android.view.ViewConfiguration; +import android.view.ViewGroup; +import android.view.ViewParent; +import android.view.animation.AnimationUtils; +import android.widget.FrameLayout; +import android.widget.Scroller; + +import java.util.List; + +/** + * Reference to ScrollView and HorizontalScrollView + */ +public class HVScrollView2 extends FrameLayout { + static final int ANIMATED_SCROLL_GAP = 250; + + static final float MAX_SCROLL_FACTOR = 0.5f; + + + private long mLastScroll; + + private final Rect mTempRect = new Rect(); + private Scroller mScroller; + + /** + * Flag to indicate that we are moving focus ourselves. This is so the + * code that watches for focus changes initiated outside this ScrollView + * knows that it does not have to do anything. + */ + private boolean mScrollViewMovedFocus; + + /** + * Position of the last motion event. + */ + private float mLastMotionY; + private float mLastMotionX; + + /** + * True when the layout has changed but the traversal has not come through yet. + * Ideally the view hierarchy would keep track of this for us. + */ + private boolean mIsLayoutDirty = true; + + /** + * The child to give focus to in the event that a child has requested focus while the + * layout is dirty. This prevents the scroll from being wrong if the child has not been + * laid out before requesting focus. + */ + private View mChildToScrollTo = null; + + /** + * True if the user is currently dragging this ScrollView around. This is + * not the same as 'is being flinged', which can be checked by + * mScroller.isFinished() (flinging begins when the user lifts his finger). + */ + private boolean mIsBeingDragged = false; + + /** + * Determines speed during touch scrolling + */ + private VelocityTracker mVelocityTracker; + + /** + * When set to true, the scroll view measure its child to make it fill the currently + * visible area. + */ + private boolean mFillViewport; + + /** + * Whether arrow scrolling is animated. + */ + private boolean mSmoothScrollingEnabled = true; + + private int mTouchSlop; + private int mMinimumVelocity; + private int mMaximumVelocity; + + /** + * ID of the active pointer. This is used to retain consistency during + * drags/flings if multiple pointers are used. + */ + private int mActivePointerId = INVALID_POINTER; + + /** + * Sentinel value for no current active pointer. + * Used by {@link #mActivePointerId}. + */ + private static final int INVALID_POINTER = -1; + + private boolean mFlingEnabled = true; + + public HVScrollView2(Context context) { + this(context, null); + } + + public HVScrollView2(Context context, AttributeSet attrs) { + super(context, attrs); + initScrollView(); + } + + @Override + protected float getTopFadingEdgeStrength() { + if (getChildCount() == 0) { + return 0.0f; + } + + final int length = getVerticalFadingEdgeLength(); + if (getScrollY() < length) { + return getScrollY() / (float) length; + } + + return 1.0f; + } + + @Override + protected float getLeftFadingEdgeStrength() { + if (getChildCount() == 0) { + return 0.0f; + } + + final int length = getHorizontalFadingEdgeLength(); + if (getScrollX() < length) { + return getScrollX() / (float) length; + } + + return 1.0f; + } + + @Override + protected float getRightFadingEdgeStrength() { + if (getChildCount() == 0) { + return 0.0f; + } + + final int length = getHorizontalFadingEdgeLength(); + final int rightEdge = getWidth() - getPaddingRight(); + final int span = getChildAt(0).getRight() - getScrollX() - rightEdge; + if (span < length) { + return span / (float) length; + } + + return 1.0f; + } + + @Override + protected float getBottomFadingEdgeStrength() { + if (getChildCount() == 0) { + return 0.0f; + } + + final int length = getVerticalFadingEdgeLength(); + final int bottomEdge = getHeight() - getPaddingBottom(); + final int span = getChildAt(0).getBottom() - getScrollY() - bottomEdge; + if (span < length) { + return span / (float) length; + } + + return 1.0f; + } + + /** + * @return The maximum amount this scroll view will scroll in response to + * an arrow event. + */ + public int getMaxScrollAmountV() { + return (int) (MAX_SCROLL_FACTOR * (getBottom() - getTop())); + } + + public int getMaxScrollAmountH() { + return (int) (MAX_SCROLL_FACTOR * (getRight() - getLeft())); + } + + + private void initScrollView() { + mScroller = new Scroller(getContext()); + setFocusable(true); + setDescendantFocusability(FOCUS_AFTER_DESCENDANTS); + setWillNotDraw(false); + final ViewConfiguration configuration = ViewConfiguration.get(getContext()); + mTouchSlop = configuration.getScaledTouchSlop(); + mMinimumVelocity = configuration.getScaledMinimumFlingVelocity(); + mMaximumVelocity = configuration.getScaledMaximumFlingVelocity(); + } + + @Override + public void addView(View child) { + if (getChildCount() > 0) { + throw new IllegalStateException("ScrollView can host only one direct child"); + } + + super.addView(child); + } + + @Override + public void addView(View child, int index) { + if (getChildCount() > 0) { + throw new IllegalStateException("ScrollView can host only one direct child"); + } + + super.addView(child, index); + } + + @Override + public void addView(View child, ViewGroup.LayoutParams params) { + if (getChildCount() > 0) { + throw new IllegalStateException("ScrollView can host only one direct child"); + } + + super.addView(child, params); + } + + @Override + public void addView(View child, int index, ViewGroup.LayoutParams params) { + if (getChildCount() > 0) { + throw new IllegalStateException("ScrollView can host only one direct child"); + } + + super.addView(child, index, params); + } + + /** + * @return Returns true this ScrollView can be scrolled + */ + private boolean canScrollV() { + View child = getChildAt(0); + if (child != null) { + int childHeight = child.getHeight(); + return getHeight() < childHeight + getPaddingTop() + getPaddingBottom(); + } + return false; + } + + private boolean canScrollH() { + View child = getChildAt(0); + if (child != null) { + int childWidth = child.getWidth(); + return getWidth() < childWidth + getPaddingLeft() + getPaddingRight(); + } + return false; + } + + /** + * Indicates whether this ScrollView's content is stretched to fill the viewport. + * + * @return True if the content fills the viewport, false otherwise. + */ + public boolean isFillViewport() { + return mFillViewport; + } + + /** + * Indicates this ScrollView whether it should stretch its content height to fill + * the viewport or not. + * + * @param fillViewport True to stretch the content's height to the viewport's + * boundaries, false otherwise. + */ + public void setFillViewport(boolean fillViewport) { + if (fillViewport != mFillViewport) { + mFillViewport = fillViewport; + requestLayout(); + } + } + + /** + * @return Whether arrow scrolling will animate its transition. + */ + public boolean isSmoothScrollingEnabled() { + return mSmoothScrollingEnabled; + } + + /** + * Set whether arrow scrolling will animate its transition. + * + * @param smoothScrollingEnabled whether arrow scrolling will animate its transition + */ + public void setSmoothScrollingEnabled(boolean smoothScrollingEnabled) { + mSmoothScrollingEnabled = smoothScrollingEnabled; + } + + @Override + protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { + super.onMeasure(widthMeasureSpec, heightMeasureSpec); + + if (!mFillViewport) { + return; + } + + final int heightMode = MeasureSpec.getMode(heightMeasureSpec); + final int widthMode = MeasureSpec.getMode(widthMeasureSpec); + if (heightMode == MeasureSpec.UNSPECIFIED && widthMode == MeasureSpec.UNSPECIFIED) { + return; + } + + if (getChildCount() > 0) { + final View child = getChildAt(0); + int height = getMeasuredHeight(); + int width = getMeasuredWidth(); + if (child.getMeasuredHeight() < height || child.getMeasuredWidth() < width) { + width -= getPaddingLeft(); + width -= getPaddingRight(); + int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY); + + height -= getPaddingTop(); + height -= getPaddingBottom(); + int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY); + + child.measure(childWidthMeasureSpec, childHeightMeasureSpec); + } + } + } + + @Override + public boolean dispatchKeyEvent(KeyEvent event) { + // Let the focused view and/or our descendants get the key first + return super.dispatchKeyEvent(event) || executeKeyEvent(event); + } + + /** + * You can call this function yourself to have the scroll view perform + * scrolling from a key event, just as if the event had been dispatched to + * it by the view hierarchy. + * + * @param event The key event to execute. + * @return Return true if the event was handled, else false. + */ + public boolean executeKeyEvent(KeyEvent event) { + mTempRect.setEmpty(); + + boolean handled = false; + + if (event.getAction() == KeyEvent.ACTION_DOWN) { + switch (event.getKeyCode()) { + case KeyEvent.KEYCODE_DPAD_LEFT: + if (canScrollH()) { + if (!event.isAltPressed()) { + handled = arrowScrollH(View.FOCUS_LEFT); + } else { + handled = fullScrollH(View.FOCUS_LEFT); + } + } + break; + case KeyEvent.KEYCODE_DPAD_RIGHT: + if (canScrollH()) { + if (!event.isAltPressed()) { + handled = arrowScrollH(View.FOCUS_RIGHT); + } else { + handled = fullScrollH(View.FOCUS_RIGHT); + } + } + break; + case KeyEvent.KEYCODE_DPAD_UP: + if (canScrollV()) { + if (!event.isAltPressed()) { + handled = arrowScrollV(View.FOCUS_UP); + } else { + handled = fullScrollV(View.FOCUS_UP); + } + } + break; + case KeyEvent.KEYCODE_DPAD_DOWN: + if (canScrollV()) { + if (!event.isAltPressed()) { + handled = arrowScrollV(View.FOCUS_DOWN); + } else { + handled = fullScrollV(View.FOCUS_DOWN); + } + } + break; + } + } + return handled; + } + + private boolean inChild(int x, int y) { + if (getChildCount() > 0) { + final int scrollX = getScrollX(); + final int scrollY = getScrollY(); + final View child = getChildAt(0); + return !(y < child.getTop() - scrollY + || y >= child.getBottom() - scrollY + || x < child.getLeft() - scrollX + || x >= child.getRight() - scrollX); + } + return false; + } + + @Override + public boolean onInterceptTouchEvent(MotionEvent ev) { + /* + * This method JUST determines whether we want to intercept the motion. + * If we return true, onMotionEvent will be called and we do the actual + * scrolling there. + */ + + /* + * Shortcut the most recurring case: the user is in the dragging + * state and he is moving his finger. We want to intercept this + * motion. + */ + final int action = ev.getAction(); + if ((action == MotionEvent.ACTION_MOVE) && (mIsBeingDragged)) { + return true; + } + + switch (action & MotionEvent.ACTION_MASK) { + case MotionEvent.ACTION_MOVE: { + /* + * mIsBeingDragged == false, otherwise the shortcut would have caught it. Check + * whether the user has moved far enough from his original down touch. + */ + + /* + * Locally do absolute value. mLastMotionY is set to the y value + * of the down event. + */ + final int activePointerId = mActivePointerId; + if (activePointerId == INVALID_POINTER) { + // If we don't have a valid id, the touch down wasn't on content. + break; + } + + final int pointerIndex = ev.findPointerIndex(activePointerId); + final float y = ev.getY(pointerIndex); + final int yDiff = (int) Math.abs(y - mLastMotionY); + if (yDiff > mTouchSlop) { + mIsBeingDragged = true; + mLastMotionY = y; + } + final float x = ev.getX(pointerIndex); + final int xDiff = (int) Math.abs(x - mLastMotionX); + if (xDiff > mTouchSlop) { + mIsBeingDragged = true; + mLastMotionX = x; + } + break; + } + + case MotionEvent.ACTION_DOWN: { + final float x = ev.getX(); + final float y = ev.getY(); + if (!inChild((int) x, (int) y)) { + mIsBeingDragged = false; + break; + } + + /* + * Remember location of down touch. + * ACTION_DOWN always refers to pointer index 0. + */ + mLastMotionY = y; + mLastMotionX = x; + mActivePointerId = ev.getPointerId(0); + + /* + * If being flinged and user touches the screen, initiate drag; + * otherwise don't. mScroller.isFinished should be false when + * being flinged. + */ + mIsBeingDragged = !mScroller.isFinished(); + break; + } + + case MotionEvent.ACTION_CANCEL: + case MotionEvent.ACTION_UP: + /* Release the drag */ + mIsBeingDragged = false; + mActivePointerId = INVALID_POINTER; + break; + case MotionEvent.ACTION_POINTER_UP: + onSecondaryPointerUp(ev); + break; + } + + /* + * The only time we want to intercept motion events is if we are in the + * drag mode. + */ + return mIsBeingDragged; + } + + @Override + public boolean onTouchEvent(MotionEvent ev) { + + if (ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) { + // Don't handle edge touches immediately -- they may actually belong to one of our + // descendants. + return false; + } + + if (mVelocityTracker == null) { + mVelocityTracker = VelocityTracker.obtain(); + } + mVelocityTracker.addMovement(ev); + + final int action = ev.getAction(); + + switch (action & MotionEvent.ACTION_MASK) { + case MotionEvent.ACTION_DOWN: { + final float x = ev.getX(); + final float y = ev.getY(); + if (!(mIsBeingDragged = inChild((int) x, (int) y))) { + return false; + } + + /* + * If being flinged and user touches, stop the fling. isFinished + * will be false if being flinged. + */ + if (!mScroller.isFinished()) { + mScroller.abortAnimation(); + } + + // Remember where the motion event started + mLastMotionY = y; + mLastMotionX = x; + mActivePointerId = ev.getPointerId(0); + break; + } + case MotionEvent.ACTION_MOVE: + if (mIsBeingDragged) { + // Scroll to follow the motion event + final int activePointerIndex = ev.findPointerIndex(mActivePointerId); + final float y = ev.getY(activePointerIndex); + final int deltaY = (int) (mLastMotionY - y); + mLastMotionY = y; + + final float x = ev.getX(activePointerIndex); + final int deltaX = (int) (mLastMotionX - x); + mLastMotionX = x; + + scrollBy(deltaX, deltaY); + } + break; + case MotionEvent.ACTION_UP: + if (mIsBeingDragged) { + if (mFlingEnabled) { + final VelocityTracker velocityTracker = mVelocityTracker; + velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity); + int initialVelocitx = (int) velocityTracker.getXVelocity(mActivePointerId); + int initialVelocity = (int) velocityTracker.getYVelocity(mActivePointerId); + + if (getChildCount() > 0) { + if (Math.abs(initialVelocitx) > initialVelocitx || Math.abs(initialVelocity) > mMinimumVelocity) { + fling(-initialVelocitx, -initialVelocity); + } + + } + } + + mActivePointerId = INVALID_POINTER; + mIsBeingDragged = false; + + if (mVelocityTracker != null) { + mVelocityTracker.recycle(); + mVelocityTracker = null; + } + } + break; + case MotionEvent.ACTION_CANCEL: + if (mIsBeingDragged && getChildCount() > 0) { + mActivePointerId = INVALID_POINTER; + mIsBeingDragged = false; + if (mVelocityTracker != null) { + mVelocityTracker.recycle(); + mVelocityTracker = null; + } + } + break; + case MotionEvent.ACTION_POINTER_UP: + onSecondaryPointerUp(ev); + break; + } + return true; + } + + private void onSecondaryPointerUp(MotionEvent ev) { + final int pointerIndex = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >> + MotionEvent.ACTION_POINTER_INDEX_SHIFT; + final int pointerId = ev.getPointerId(pointerIndex); + if (pointerId == mActivePointerId) { + // This was our active pointer going up. Choose a new + // active pointer and adjust accordingly. + final int newPointerIndex = pointerIndex == 0 ? 1 : 0; + mLastMotionX = ev.getX(newPointerIndex); + mLastMotionY = ev.getY(newPointerIndex); + mActivePointerId = ev.getPointerId(newPointerIndex); + if (mVelocityTracker != null) { + mVelocityTracker.clear(); + } + } + } + + /** + *

+ * Finds the next focusable component that fits in the specified bounds. + *

+ * + * @param topFocus look for a candidate is the one at the top of the bounds + * if topFocus is true, or at the bottom of the bounds if topFocus is + * false + * @param top the top offset of the bounds in which a focusable must be + * found + * @param bottom the bottom offset of the bounds in which a focusable must + * be found + * @return the next focusable component in the bounds or null if none can + * be found + */ + private View findFocusableViewInBoundsV(boolean topFocus, int top, int bottom) { + + List focusables = getFocusables(View.FOCUS_FORWARD); + View focusCandidate = null; + + /* + * A fully contained focusable is one where its top is below the bound's + * top, and its bottom is above the bound's bottom. A partially + * contained focusable is one where some part of it is within the + * bounds, but it also has some part that is not within bounds. A fully contained + * focusable is preferred to a partially contained focusable. + */ + boolean foundFullyContainedFocusable = false; + + int count = focusables.size(); + for (int i = 0; i < count; i++) { + View view = focusables.get(i); + int viewTop = view.getTop(); + int viewBottom = view.getBottom(); + + if (top < viewBottom && viewTop < bottom) { + /* + * the focusable is in the target area, it is a candidate for + * focusing + */ + + final boolean viewIsFullyContained = (top < viewTop) && + (viewBottom < bottom); + + if (focusCandidate == null) { + /* No candidate, take this one */ + focusCandidate = view; + foundFullyContainedFocusable = viewIsFullyContained; + } else { + final boolean viewIsCloserToBoundary = + (topFocus && viewTop < focusCandidate.getTop()) || + (!topFocus && viewBottom > focusCandidate + .getBottom()); + + if (foundFullyContainedFocusable) { + if (viewIsFullyContained && viewIsCloserToBoundary) { + /* + * We're dealing with only fully contained views, so + * it has to be closer to the boundary to beat our + * candidate + */ + focusCandidate = view; + } + } else { + if (viewIsFullyContained) { + /* Any fully contained view beats a partially contained view */ + focusCandidate = view; + foundFullyContainedFocusable = true; + } else if (viewIsCloserToBoundary) { + /* + * Partially contained view beats another partially + * contained view if it's closer + */ + focusCandidate = view; + } + } + } + } + } + + return focusCandidate; + } + + private View findFocusableViewInBoundsH(boolean leftFocus, int left, int right) { + + List focusables = getFocusables(View.FOCUS_FORWARD); + View focusCandidate = null; + + /* + * A fully contained focusable is one where its left is below the bound's + * left, and its right is above the bound's right. A partially + * contained focusable is one where some part of it is within the + * bounds, but it also has some part that is not within bounds. A fully contained + * focusable is preferred to a partially contained focusable. + */ + boolean foundFullyContainedFocusable = false; + + int count = focusables.size(); + for (int i = 0; i < count; i++) { + View view = focusables.get(i); + int viewLeft = view.getLeft(); + int viewRight = view.getRight(); + + if (left < viewRight && viewLeft < right) { + /* + * the focusable is in the target area, it is a candidate for + * focusing + */ + + final boolean viewIsFullyContained = (left < viewLeft) && + (viewRight < right); + + if (focusCandidate == null) { + /* No candidate, take this one */ + focusCandidate = view; + foundFullyContainedFocusable = viewIsFullyContained; + } else { + final boolean viewIsCloserToBoundary = + (leftFocus && viewLeft < focusCandidate.getLeft()) || + (!leftFocus && viewRight > focusCandidate.getRight()); + + if (foundFullyContainedFocusable) { + if (viewIsFullyContained && viewIsCloserToBoundary) { + /* + * We're dealing with only fully contained views, so + * it has to be closer to the boundary to beat our + * candidate + */ + focusCandidate = view; + } + } else { + if (viewIsFullyContained) { + /* Any fully contained view beats a partially contained view */ + focusCandidate = view; + foundFullyContainedFocusable = true; + } else if (viewIsCloserToBoundary) { + /* + * Partially contained view beats another partially + * contained view if it's closer + */ + focusCandidate = view; + } + } + } + } + } + + return focusCandidate; + } + + /** + *

Handles scrolling in response to a "home/end" shortcut press. This + * method will scroll the view to the top or bottom and give the focus + * to the topmost/bottommost component in the new visible area. If no + * component is a good candidate for focus, this scrollview reclaims the + * focus.

+ * + * @param direction the scroll direction: {@link android.view.View#FOCUS_UP} + * to go the top of the view or + * {@link android.view.View#FOCUS_DOWN} to go the bottom + * @return true if the key event is consumed by this method, false otherwise + */ + public boolean fullScrollV(int direction) { + boolean down = direction == View.FOCUS_DOWN; + int height = getHeight(); + + mTempRect.top = 0; + mTempRect.bottom = height; + + if (down) { + int count = getChildCount(); + if (count > 0) { + View view = getChildAt(count - 1); + mTempRect.bottom = view.getBottom(); + mTempRect.top = mTempRect.bottom - height; + } + } + + return scrollAndFocusV(direction, mTempRect.top, mTempRect.bottom); + } + + public boolean fullScrollH(int direction) { + boolean right = direction == View.FOCUS_RIGHT; + int width = getWidth(); + + mTempRect.left = 0; + mTempRect.right = width; + + if (right) { + int count = getChildCount(); + if (count > 0) { + View view = getChildAt(0); + mTempRect.right = view.getRight(); + mTempRect.left = mTempRect.right - width; + } + } + + return scrollAndFocusH(direction, mTempRect.left, mTempRect.right); + } + + /** + *

Scrolls the view to make the area defined by top and + * bottom visible. This method attempts to give the focus + * to a component visible in this area. If no component can be focused in + * the new visible area, the focus is reclaimed by this scrollview.

+ * + * @param direction the scroll direction: {@link android.view.View#FOCUS_UP} + * to go upward + * {@link android.view.View#FOCUS_DOWN} to downward + * @param top the top offset of the new area to be made visible + * @param bottom the bottom offset of the new area to be made visible + * @return true if the key event is consumed by this method, false otherwise + */ + private boolean scrollAndFocusV(int direction, int top, int bottom) { + boolean handled = true; + + int height = getHeight(); + int containerTop = getScrollY(); + int containerBottom = containerTop + height; + boolean up = direction == View.FOCUS_UP; + + View newFocused = findFocusableViewInBoundsV(up, top, bottom); + if (newFocused == null) { + newFocused = this; + } + + if (top >= containerTop && bottom <= containerBottom) { + handled = false; + } else { + int delta = up ? (top - containerTop) : (bottom - containerBottom); + doScrollY(delta); + } + + if (newFocused != findFocus() && newFocused.requestFocus(direction)) { + mScrollViewMovedFocus = true; + mScrollViewMovedFocus = false; + } + + return handled; + } + + private boolean scrollAndFocusH(int direction, int left, int right) { + boolean handled = true; + + int width = getWidth(); + int containerLeft = getScrollX(); + int containerRight = containerLeft + width; + boolean goLeft = direction == View.FOCUS_LEFT; + + View newFocused = findFocusableViewInBoundsH(goLeft, left, right); + if (newFocused == null) { + newFocused = this; + } + + if (left >= containerLeft && right <= containerRight) { + handled = false; + } else { + int delta = goLeft ? (left - containerLeft) : (right - containerRight); + doScrollX(delta); + } + + if (newFocused != findFocus() && newFocused.requestFocus(direction)) { + mScrollViewMovedFocus = true; + mScrollViewMovedFocus = false; + } + + return handled; + } + + /** + * Handle scrolling in response to an up or down arrow click. + * + * @param direction The direction corresponding to the arrow key that was + * pressed + * @return True if we consumed the event, false otherwise + */ + public boolean arrowScrollV(int direction) { + + View currentFocused = findFocus(); + if (currentFocused == this) currentFocused = null; + + View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, direction); + + final int maxJump = getMaxScrollAmountV(); + + if (nextFocused != null && isWithinDeltaOfScreenV(nextFocused, maxJump, getHeight())) { + nextFocused.getDrawingRect(mTempRect); + offsetDescendantRectToMyCoords(nextFocused, mTempRect); + int scrollDelta = computeScrollDeltaToGetChildRectOnScreenV(mTempRect); + doScrollY(scrollDelta); + nextFocused.requestFocus(direction); + } else { + // no new focus + int scrollDelta = maxJump; + + if (direction == View.FOCUS_UP && getScrollY() < scrollDelta) { + scrollDelta = getScrollY(); + } else if (direction == View.FOCUS_DOWN) { + if (getChildCount() > 0) { + int daBottom = getChildAt(0).getBottom(); + + int screenBottom = getScrollY() + getHeight(); + + if (daBottom - screenBottom < maxJump) { + scrollDelta = daBottom - screenBottom; + } + } + } + if (scrollDelta == 0) { + return false; + } + doScrollY(direction == View.FOCUS_DOWN ? scrollDelta : -scrollDelta); + } + + if (currentFocused != null && currentFocused.isFocused() + && isOffScreenV(currentFocused)) { + // previously focused item still has focus and is off screen, give + // it up (take it back to ourselves) + // (also, need to temporarily force FOCUS_BEFORE_DESCENDANTS so we are + // sure to + // get it) + final int descendantFocusability = getDescendantFocusability(); // save + setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS); + requestFocus(); + setDescendantFocusability(descendantFocusability); // restore + } + return true; + } + + public boolean arrowScrollH(int direction) { + + View currentFocused = findFocus(); + if (currentFocused == this) currentFocused = null; + + View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, direction); + + final int maxJump = getMaxScrollAmountH(); + + if (nextFocused != null && isWithinDeltaOfScreenH(nextFocused, maxJump)) { + nextFocused.getDrawingRect(mTempRect); + offsetDescendantRectToMyCoords(nextFocused, mTempRect); + int scrollDelta = computeScrollDeltaToGetChildRectOnScreenH(mTempRect); + doScrollX(scrollDelta); + nextFocused.requestFocus(direction); + } else { + // no new focus + int scrollDelta = maxJump; + + if (direction == View.FOCUS_LEFT && getScrollX() < scrollDelta) { + scrollDelta = getScrollX(); + } else if (direction == View.FOCUS_RIGHT && getChildCount() > 0) { + + int daRight = getChildAt(0).getRight(); + + int screenRight = getScrollX() + getWidth(); + + if (daRight - screenRight < maxJump) { + scrollDelta = daRight - screenRight; + } + } + if (scrollDelta == 0) { + return false; + } + doScrollX(direction == View.FOCUS_RIGHT ? scrollDelta : -scrollDelta); + } + + if (currentFocused != null && currentFocused.isFocused() + && isOffScreenH(currentFocused)) { + // previously focused item still has focus and is off screen, give + // it up (take it back to ourselves) + // (also, need to temporarily force FOCUS_BEFORE_DESCENDANTS so we are + // sure to + // get it) + final int descendantFocusability = getDescendantFocusability(); // save + setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS); + requestFocus(); + setDescendantFocusability(descendantFocusability); // restore + } + return true; + } + + /** + * @return whether the descendant of this scroll view is scrolled off + * screen. + */ + private boolean isOffScreenV(View descendant) { + return !isWithinDeltaOfScreenV(descendant, 0, getHeight()); + } + + private boolean isOffScreenH(View descendant) { + return !isWithinDeltaOfScreenH(descendant, 0); + } + + /** + * @return whether the descendant of this scroll view is within delta + * pixels of being on the screen. + */ + private boolean isWithinDeltaOfScreenV(View descendant, int delta, int height) { + descendant.getDrawingRect(mTempRect); + offsetDescendantRectToMyCoords(descendant, mTempRect); + + return (mTempRect.bottom + delta) >= getScrollY() + && (mTempRect.top - delta) <= (getScrollY() + height); + } + + private boolean isWithinDeltaOfScreenH(View descendant, int delta) { + descendant.getDrawingRect(mTempRect); + offsetDescendantRectToMyCoords(descendant, mTempRect); + + return (mTempRect.right + delta) >= getScrollX() + && (mTempRect.left - delta) <= (getScrollX() + getWidth()); + } + + /** + * Smooth scroll by a Y delta + * + * @param delta the number of pixels to scroll by on the Y axis + */ + private void doScrollY(int delta) { + if (delta != 0) { + if (mSmoothScrollingEnabled) { + smoothScrollBy(0, delta); + } else { + scrollBy(0, delta); + } + } + } + + private void doScrollX(int delta) { + if (delta != 0) { + if (mSmoothScrollingEnabled) { + smoothScrollBy(delta, 0); + } else { + scrollBy(delta, 0); + } + } + } + + /** + * Like {@link View#scrollBy}, but scroll smoothly instead of immediately. + * + * @param dx the number of pixels to scroll by on the X axis + * @param dy the number of pixels to scroll by on the Y axis + */ + public void smoothScrollBy(int dx, int dy) { + if (getChildCount() == 0) { + // Nothing to do. + return; + } + long duration = AnimationUtils.currentAnimationTimeMillis() - mLastScroll; + if (duration > ANIMATED_SCROLL_GAP) { + final int height = getHeight() - getPaddingBottom() - getPaddingTop(); + final int bottom = getChildAt(0).getHeight(); + final int maxY = Math.max(0, bottom - height); + final int scrollY = getScrollY(); + dy = Math.max(0, Math.min(scrollY + dy, maxY)) - scrollY; + + final int width = getWidth() - getPaddingRight() - getPaddingLeft(); + final int right = getChildAt(0).getWidth(); + final int maxX = Math.max(0, right - width); + final int scrollX = getScrollX(); + dx = Math.max(0, Math.min(scrollX + dx, maxX)) - scrollX; + + mScroller.startScroll(scrollX, scrollY, dx, dy); + invalidate(); + } else { + if (!mScroller.isFinished()) { + mScroller.abortAnimation(); + } + scrollBy(dx, dy); + } + mLastScroll = AnimationUtils.currentAnimationTimeMillis(); + } + + /** + * Like {@link #scrollTo}, but scroll smoothly instead of immediately. + * + * @param x the position where to scroll on the X axis + * @param y the position where to scroll on the Y axis + */ + public final void smoothScrollTo(int x, int y) { + smoothScrollBy(x - getScrollX(), y - getScrollY()); + } + + /** + *

The scroll range of a scroll view is the overall height of all of its + * children.

+ */ + @Override + protected int computeVerticalScrollRange() { + final int count = getChildCount(); + final int contentHeight = getHeight() - getPaddingBottom() - getPaddingTop(); + if (count == 0) { + return contentHeight; + } + + return getChildAt(0).getBottom(); + } + + @Override + protected int computeHorizontalScrollRange() { + final int count = getChildCount(); + final int contentWidth = getWidth() - getPaddingLeft() - getPaddingRight(); + if (count == 0) { + return contentWidth; + } + + return getChildAt(0).getRight(); + } + + @Override + protected int computeVerticalScrollOffset() { + return Math.max(0, super.computeVerticalScrollOffset()); + } + + @Override + protected int computeHorizontalScrollOffset() { + return Math.max(0, super.computeHorizontalScrollOffset()); + } + + @Override + protected void measureChild(View child, int parentWidthMeasureSpec, int parentHeightMeasureSpec) { + int childWidthMeasureSpec; + int childHeightMeasureSpec; + + childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); + + childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); + + child.measure(childWidthMeasureSpec, childHeightMeasureSpec); + } + + @Override + protected void measureChildWithMargins(View child, int parentWidthMeasureSpec, int widthUsed, + int parentHeightMeasureSpec, int heightUsed) { + final MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams(); + + final int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec( + lp.leftMargin + lp.rightMargin, MeasureSpec.UNSPECIFIED); + final int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec( + lp.topMargin + lp.bottomMargin, MeasureSpec.UNSPECIFIED); + + child.measure(childWidthMeasureSpec, childHeightMeasureSpec); + } + + @Override + public void computeScroll() { + if (mScroller.computeScrollOffset()) { + // This is called at drawing time by ViewGroup. We don't want to + // re-show the scrollbars at this point, which scrollTo will do, + // so we replicate most of scrollTo here. + // + // It's a little odd to call onScrollChanged from inside the drawing. + // + // It is, except when you remember that computeScroll() is used to + // animate scrolling. So unless we want to defer the onScrollChanged() + // until the end of the animated scrolling, we don't really have a + // choice here. + // + // I agree. The alternative, which I think would be worse, is to post + // something and tell the subclasses later. This is bad because there + // will be a window where mScrollX/Y is different from what the app + // thinks it is. + // + int x = mScroller.getCurrX(); + int y = mScroller.getCurrY(); + + if (getChildCount() > 0) { + View child = getChildAt(0); + x = clamp(x, getWidth() - getPaddingRight() - getPaddingLeft(), child.getWidth()); + y = clamp(y, getHeight() - getPaddingBottom() - getPaddingTop(), child.getHeight()); + super.scrollTo(x, y); + } + awakenScrollBars(); + + // Keep on drawing until the animation has finished. + postInvalidate(); + } + } + + /** + * Scrolls the view to the given child. + * + * @param child the View to scroll to + */ + private void scrollToChild(View child) { + child.getDrawingRect(mTempRect); + + /* Offset from child's local coordinates to ScrollView coordinates */ + offsetDescendantRectToMyCoords(child, mTempRect); + + int scrollDeltaV = computeScrollDeltaToGetChildRectOnScreenV(mTempRect); + int scrollDeltaH = computeScrollDeltaToGetChildRectOnScreenH(mTempRect); + + if (scrollDeltaH != 0 || scrollDeltaV != 0) { + scrollBy(scrollDeltaH, scrollDeltaV); + } + } + + /** + * If rect is off screen, scroll just enough to get it (or at least the + * first screen size chunk of it) on screen. + * + * @param rect The rectangle. + * @param immediate True to scroll immediately without animation + * @return true if scrolling was performed + */ + private boolean scrollToChildRect(Rect rect, boolean immediate) { + final int deltaV = computeScrollDeltaToGetChildRectOnScreenV(rect); + final int deltaH = computeScrollDeltaToGetChildRectOnScreenH(rect); + final boolean scroll = deltaH != 0 || deltaV != 0; + if (scroll) { + if (immediate) { + scrollBy(deltaH, deltaV); + } else { + smoothScrollBy(deltaH, deltaV); + } + } + return scroll; + } + + /** + * Compute the amount to scroll in the Y direction in order to get + * a rectangle completely on the screen (or, if taller than the screen, + * at least the first screen size chunk of it). + * + * @param rect The rect. + * @return The scroll delta. + */ + protected int computeScrollDeltaToGetChildRectOnScreenV(Rect rect) { + if (getChildCount() == 0) return 0; + + int height = getHeight(); + int screenTop = getScrollY(); + int screenBottom = screenTop + height; + + int fadingEdge = getVerticalFadingEdgeLength(); + + // leave room for top fading edge as long as rect isn't at very top + if (rect.top > 0) { + screenTop += fadingEdge; + } + + // leave room for bottom fading edge as long as rect isn't at very bottom + if (rect.bottom < getChildAt(0).getHeight()) { + screenBottom -= fadingEdge; + } + + int scrollYDelta = 0; + + if (rect.bottom > screenBottom && rect.top > screenTop) { + // need to move down to get it in view: move down just enough so + // that the entire rectangle is in view (or at least the first + // screen size chunk). + + if (rect.height() > height) { + // just enough to get screen size chunk on + scrollYDelta += (rect.top - screenTop); + } else { + // get entire rect at bottom of screen + scrollYDelta += (rect.bottom - screenBottom); + } + + // make sure we aren't scrolling beyond the end of our content + int bottom = getChildAt(0).getBottom(); + int distanceToBottom = bottom - screenBottom; + scrollYDelta = Math.min(scrollYDelta, distanceToBottom); + + } else if (rect.top < screenTop && rect.bottom < screenBottom) { + // need to move up to get it in view: move up just enough so that + // entire rectangle is in view (or at least the first screen + // size chunk of it). + + if (rect.height() > height) { + // screen size chunk + scrollYDelta -= (screenBottom - rect.bottom); + } else { + // entire rect at top + scrollYDelta -= (screenTop - rect.top); + } + + // make sure we aren't scrolling any further than the top our content + scrollYDelta = Math.max(scrollYDelta, -getScrollY()); + } + return scrollYDelta; + } + + protected int computeScrollDeltaToGetChildRectOnScreenH(Rect rect) { + if (getChildCount() == 0) return 0; + + int width = getWidth(); + int screenLeft = getScrollX(); + int screenRight = screenLeft + width; + + int fadingEdge = getHorizontalFadingEdgeLength(); + + // leave room for left fading edge as long as rect isn't at very left + if (rect.left > 0) { + screenLeft += fadingEdge; + } + + // leave room for right fading edge as long as rect isn't at very right + if (rect.right < getChildAt(0).getWidth()) { + screenRight -= fadingEdge; + } + + int scrollXDelta = 0; + + if (rect.right > screenRight && rect.left > screenLeft) { + // need to move right to get it in view: move right just enough so + // that the entire rectangle is in view (or at least the first + // screen size chunk). + + if (rect.width() > width) { + // just enough to get screen size chunk on + scrollXDelta += (rect.left - screenLeft); + } else { + // get entire rect at right of screen + scrollXDelta += (rect.right - screenRight); + } + + // make sure we aren't scrolling beyond the end of our content + int right = getChildAt(0).getRight(); + int distanceToRight = right - screenRight; + scrollXDelta = Math.min(scrollXDelta, distanceToRight); + + } else if (rect.left < screenLeft && rect.right < screenRight) { + // need to move right to get it in view: move right just enough so that + // entire rectangle is in view (or at least the first screen + // size chunk of it). + + if (rect.width() > width) { + // screen size chunk + scrollXDelta -= (screenRight - rect.right); + } else { + // entire rect at left + scrollXDelta -= (screenLeft - rect.left); + } + + // make sure we aren't scrolling any further than the left our content + scrollXDelta = Math.max(scrollXDelta, -getScrollX()); + } + return scrollXDelta; + } + + @Override + public void requestChildFocus(View child, View focused) { + if (!mScrollViewMovedFocus) { + if (!mIsLayoutDirty) { + scrollToChild(focused); + } else { + // The child may not be laid out yet, we can't compute the scroll yet + mChildToScrollTo = focused; + } + } + super.requestChildFocus(child, focused); + } + + + /** + * When looking for focus in children of a scroll view, need to be a little + * more careful not to give focus to something that is scrolled off screen. + *

+ * This is more expensive than the default {@link android.view.ViewGroup} + * implementation, otherwise this behavior might have been made the default. + */ + @Override + protected boolean onRequestFocusInDescendants(int direction, + Rect previouslyFocusedRect) { + + // convert from forward / backward notation to up / down / left / right + // (ugh). + // TODO: FUCK +// if (direction == View.FOCUS_FORWARD) { +// direction = View.FOCUS_RIGHT; +// } else if (direction == View.FOCUS_BACKWARD) { +// direction = View.FOCUS_LEFT; +// } + + final View nextFocus = previouslyFocusedRect == null ? + FocusFinder.getInstance().findNextFocus(this, null, direction) : + FocusFinder.getInstance().findNextFocusFromRect(this, + previouslyFocusedRect, direction); + + if (nextFocus == null) { + return false; + } + +// if (isOffScreenH(nextFocus)) { +// return false; +// } + + return nextFocus.requestFocus(direction, previouslyFocusedRect); + } + + @Override + public boolean requestChildRectangleOnScreen(View child, Rect rectangle, + boolean immediate) { + // offset into coordinate space of this scroll view + rectangle.offset(child.getLeft() - child.getScrollX(), + child.getTop() - child.getScrollY()); + + return scrollToChildRect(rectangle, immediate); + } + + @Override + public void requestLayout() { + mIsLayoutDirty = true; + super.requestLayout(); + } + + @Override + protected void onLayout(boolean changed, int l, int t, int r, int b) { + super.onLayout(changed, l, t, r, b); + mIsLayoutDirty = false; + // Give a child focus if it needs it + if (mChildToScrollTo != null && isViewDescendantOf(mChildToScrollTo, this)) { + scrollToChild(mChildToScrollTo); + } + mChildToScrollTo = null; + + // Calling this with the present values causes it to re-clam them + scrollTo(getScrollX(), getScrollY()); + } + + @Override + protected void onSizeChanged(int w, int h, int oldw, int oldh) { + super.onSizeChanged(w, h, oldw, oldh); + + View currentFocused = findFocus(); + if (null == currentFocused || this == currentFocused) + return; + + // If the currently-focused view was visible on the screen when the + // screen was at the old height, then scroll the screen to make that + // view visible with the new screen height. + if (isWithinDeltaOfScreenV(currentFocused, 0, oldh)) { + currentFocused.getDrawingRect(mTempRect); + offsetDescendantRectToMyCoords(currentFocused, mTempRect); + int scrollDelta = computeScrollDeltaToGetChildRectOnScreenV(mTempRect); + doScrollY(scrollDelta); + } + + final int maxJump = getRight() - getLeft(); + if (isWithinDeltaOfScreenH(currentFocused, maxJump)) { + currentFocused.getDrawingRect(mTempRect); + offsetDescendantRectToMyCoords(currentFocused, mTempRect); + int scrollDelta = computeScrollDeltaToGetChildRectOnScreenH(mTempRect); + doScrollX(scrollDelta); + } + } + + /** + * Return true if child is an descendant of parent, (or equal to the parent). + */ + private boolean isViewDescendantOf(View child, View parent) { + if (child == parent) { + return true; + } + + final ViewParent theParent = child.getParent(); + return (theParent instanceof ViewGroup) && isViewDescendantOf((View) theParent, parent); + } + + /** + * Fling the scroll view + * + * @param velocityY The initial velocity in the Y direction. Positive + * numbers mean that the finger/cursor is moving down the screen, + * which means we want to scroll towards the top. + */ + public void fling(int velocityX, int velocityY) { + if (getChildCount() > 0) { + int width = getWidth() - getPaddingRight() - getPaddingLeft(); + int right = getChildAt(0).getWidth(); + + int height = getHeight() - getPaddingBottom() - getPaddingTop(); + int bottom = getChildAt(0).getHeight(); + + mScroller.fling(getScrollX(), getScrollY(), velocityX, velocityY, + 0, Math.max(0, right - width), + 0, Math.max(0, bottom - height)); + +// final boolean movingDown = velocityX > 0 || velocityY > 0; +// +// View newFocused = +// findFocusableViewInMyBoundsV(movingDown, mScroller.getFinalY(), findFocus()); +// if (newFocused == null) { +// newFocused = this; +// } +// +// if (newFocused != findFocus() +// && newFocused.requestFocus(movingDown ? View.FOCUS_DOWN : View.FOCUS_UP)) { +// mScrollViewMovedFocus = true; +// mScrollViewMovedFocus = false; +// } + + invalidate(); + } + } + + /** + * {@inheritDoc} + * + *

This version also clamps the scrolling to the bounds of our child. + */ + @Override + public void scrollTo(int x, int y) { + // we rely on the fact the View.scrollBy calls scrollTo. + if (getChildCount() > 0) { + View child = getChildAt(0); + x = clamp(x, getWidth() - getPaddingRight() - getPaddingLeft(), child.getWidth()); + y = clamp(y, getHeight() - getPaddingBottom() - getPaddingTop(), child.getHeight()); + if (x != getScrollX() || y != getScrollY()) { + super.scrollTo(x, y); + } + } + } + + private int clamp(int n, int my, int child) { + if (my >= child || n < 0) { + /* my >= child is this case: + * |--------------- me ---------------| + * |------ child ------| + * or + * |--------------- me ---------------| + * |------ child ------| + * or + * |--------------- me ---------------| + * |------ child ------| + * + * n < 0 is this case: + * |------ me ------| + * |-------- child --------| + * |-- mScrollX --| + */ + return 0; + } + if ((my + n) > child) { + /* this case: + * |------ me ------| + * |------ child ------| + * |-- mScrollX --| + */ + return child - my; + } + return n; + } + + public boolean isFlingEnabled() { + return mFlingEnabled; + } + + public void setFlingEnabled(boolean flingEnabled) { + this.mFlingEnabled = flingEnabled; + } +} \ No newline at end of file