Android: implement slider style gallery

doric-android/doric/src/main/java/pub/doric/shader/slider/SlideAdapter.java

@@ -20,16 +20,18 @@ import android.util.SparseArray;
 import android.view.View;
 import android.view.ViewGroup;
 
+import androidx.annotation.NonNull;
+import androidx.recyclerview.widget.RecyclerView;
+
 import com.github.pengfeizhou.jscore.JSArray;
 import com.github.pengfeizhou.jscore.JSDecoder;
 import com.github.pengfeizhou.jscore.JSNull;
 import com.github.pengfeizhou.jscore.JSObject;
 import com.github.pengfeizhou.jscore.JSValue;
 
-import androidx.annotation.NonNull;
-import androidx.recyclerview.widget.RecyclerView;
 import pub.doric.async.AsyncResult;
 import pub.doric.shader.ViewNode;
+import pub.doric.utils.DoricUtils;
 
 /**
  * @Description: pub.doric.shader.slider
@@ -46,6 +48,8 @@ class SlideAdapter extends RecyclerView.Adapter<SlideAdapter.DoricViewHolder> {
     String renderPageFuncId;
     boolean loop;
 
+    float itemWidth;
+
     SlideAdapter(SliderNode sliderNode) {
         this.sliderNode = sliderNode;
     }
@@ -71,6 +75,10 @@ class SlideAdapter extends RecyclerView.Adapter<SlideAdapter.DoricViewHolder> {
         } catch (Exception e) {
             sliderNode.getDoricContext().getDriver().getRegistry().onException(sliderNode.getDoricContext(), e);
         }
+
+        if (sliderNode.slideStyle.equals("gallery")) {
+            holder.itemView.getLayoutParams().width = DoricUtils.dp2px(this.itemWidth);
+        }
     }
 
     @Override
@@ -149,6 +157,10 @@ class SlideAdapter extends RecyclerView.Adapter<SlideAdapter.DoricViewHolder> {
         }
     }
 
+    void setItemWidth(float itemWidth) {
+        this.itemWidth = itemWidth;
+    }
+
     static class DoricViewHolder extends RecyclerView.ViewHolder {
         SlideItemNode slideItemNode;
 

doric-android/doric/src/main/java/pub/doric/shader/slider/SliderLayoutManager.java

@@ -0,0 +1,97 @@
+package pub.doric.shader.slider;
+
+import android.content.Context;
+import android.view.View;
+
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+
+import pub.doric.utils.DoricUtils;
+
+public class SliderLayoutManager extends LinearLayoutManager {
+
+    private boolean enableGallery;
+    private float minScale = 1f;
+    private float itemWidth = 0;
+
+    private float minAlpha = 1f;
+
+    public SliderLayoutManager(Context context, int orientation, boolean reverseLayout) {
+        super(context, orientation, reverseLayout);
+    }
+
+    @Override
+    public int scrollHorizontallyBy(int dx, RecyclerView.Recycler recycler, RecyclerView.State state) {
+        if (enableGallery) {
+            handleHorizontalView();
+        }
+        return super.scrollHorizontallyBy(dx, recycler, state);
+    }
+
+    @Override
+    public void onLayoutCompleted(RecyclerView.State state) {
+        super.onLayoutCompleted(state);
+
+        //scroll won't be called when first layout completed, so need to handle view at first time
+        if (enableGallery) {
+            handleView();
+        }
+    }
+
+    public void setEnableGallery(boolean enableGallery) {
+        this.enableGallery = enableGallery;
+    }
+
+    public void setItemWidth(float itemWidth) {
+        this.itemWidth = itemWidth;
+    }
+
+    public void setMinScale(float minScale) {
+        this.minScale = minScale;
+    }
+
+    public void setMinAlpha(float minAlpha) {
+        this.minAlpha = minAlpha;
+    }
+
+    private void handleView() {
+        if (getOrientation() == LinearLayoutManager.HORIZONTAL) {
+            handleHorizontalView();
+        }
+    }
+
+    private void handleHorizontalView() {
+        float centerViewLeft = (float) (getWidth() - DoricUtils.dp2px(this.itemWidth)) / 2;//the left when the view is centered
+        float moveX = DoricUtils.dp2px(this.itemWidth);//movement x from one item to another
+        calculateScale(centerViewLeft, moveX);
+    }
+
+    private void calculateScale(float centerViewLeft, float moveDistance) {
+        for (int i = 0; i < getChildCount(); i++) {
+            View child = getChildAt(i);
+            assert child != null;
+            int left = child.getLeft();
+            if (getOrientation() == LinearLayoutManager.VERTICAL) {
+                left = child.getTop();
+            }
+            float factor = (left - centerViewLeft) / moveDistance;
+            factor = Math.max(-1f, factor);
+            factor = Math.min(1f, factor);
+            if (factor > 0) {
+                // right view to center
+                scaleAndAlpha(child, 1f - factor * (1 - minScale), 1 - factor * (1 - minAlpha));
+            } else {
+                // left view to center
+                scaleAndAlpha(child, 1f + factor * (1 - minScale), 1 + factor * (1 - minAlpha));
+            }
+        }
+    }
+
+    private void scaleAndAlpha(View view, float scale, float alpha) {
+        view.setPivotX(view.getWidth() / 2f);
+        view.setPivotY(view.getHeight() / 2f);
+        view.setScaleX(scale);
+        view.setScaleY(scale);
+        view.setAlpha(alpha);
+    }
+}

doric-android/doric/src/main/java/pub/doric/shader/slider/SliderNode.java

@@ -17,6 +17,7 @@ package pub.doric.shader.slider;
 
 import android.annotation.SuppressLint;
 import android.content.Context;
+import android.graphics.Rect;
 import android.text.TextUtils;
 import android.view.View;
 
@@ -35,6 +36,7 @@ import pub.doric.extension.bridge.DoricPlugin;
 import pub.doric.extension.bridge.DoricPromise;
 import pub.doric.shader.SuperNode;
 import pub.doric.shader.ViewNode;
+import pub.doric.utils.DoricUtils;
 
 /**
  * @Description: pub.doric.shader.slider
@@ -50,9 +52,10 @@ public class SliderNode extends SuperNode<RecyclerView> {
     private boolean loop = false;
     private String renderPageFuncId;
     private boolean scrollable = true;
-    private String slideStyle = null;
+    String slideStyle = null;
     private float minScale = 0.618f;
     private float maxScale = 1;
+    private float galleryItemWidth = -1f;
 
     private int slidePosition;
     private boolean needSlideToPosition;
@@ -64,10 +67,10 @@ public class SliderNode extends SuperNode<RecyclerView> {
 
     @Override
     protected RecyclerView build() {
-        RecyclerView recyclerView = new RecyclerView(getContext());
+        final RecyclerView recyclerView = new RecyclerView(getContext());
 
 
-        final LinearLayoutManager layoutManager = new LinearLayoutManager(getContext()) {
+        final SliderLayoutManager layoutManager = new SliderLayoutManager(getContext(), LinearLayoutManager.HORIZONTAL, false) {
             @Override
             public boolean canScrollHorizontally() {
                 if (!scrollable) {
@@ -88,10 +91,28 @@ public class SliderNode extends SuperNode<RecyclerView> {
             }
         };
 
-        layoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
         recyclerView.setLayoutManager(layoutManager);
         final PagerSnapHelper snapHelper = new PagerSnapHelper();
         snapHelper.attachToRecyclerView(recyclerView);
+
+        recyclerView.addItemDecoration(new RecyclerView.ItemDecoration() {
+            @Override
+            public void getItemOffsets(@NonNull Rect outRect, @NonNull View view, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
+                if (slideStyle.equals("gallery")) {
+                    int position = parent.getChildAdapterPosition(view);
+
+                    LinearLayoutManager layoutManager = (LinearLayoutManager) parent.getLayoutManager();
+                    assert layoutManager != null;
+                    int count = layoutManager.getItemCount();
+                    int interval = (recyclerView.getWidth() - DoricUtils.dp2px(SliderNode.this.galleryItemWidth)) / 2;
+                    if (position == 0) {
+                        outRect.left = interval;
+                    } else if (position == count - 1) {
+                        outRect.right = interval;
+                    }
+                }
+            }
+        });
         recyclerView.setAdapter(this.slideAdapter);
         recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
             @Override
@@ -255,8 +276,24 @@ public class SliderNode extends SuperNode<RecyclerView> {
                     this.slideStyle = prop.asString().value();
                 } else if (prop.isObject()) {
                     this.slideStyle = prop.asObject().getProperty("type").asString().value();
+                    if (this.slideStyle.equals("zoomOut")) {
                         this.maxScale = prop.asObject().getProperty("maxScale").asNumber().toFloat();
                         this.minScale = prop.asObject().getProperty("minScale").asNumber().toFloat();
+                    } else if (this.slideStyle.equals("gallery")) {
+                        float galleryMinScale = prop.asObject().getProperty("minScale").asNumber().toFloat();
+                        float galleryMinAlpha = prop.asObject().getProperty("minAlpha").asNumber().toFloat();
+                        this.galleryItemWidth = prop.asObject().getProperty("itemWidth").asNumber().toFloat();
+
+                        SliderLayoutManager layoutManager = (SliderLayoutManager) mView.getLayoutManager();
+                        if (layoutManager != null) {
+                            layoutManager.setEnableGallery(true);
+                            layoutManager.setMinScale(galleryMinScale);
+                            layoutManager.setMinAlpha(galleryMinAlpha);
+                            layoutManager.setItemWidth(this.galleryItemWidth);
+                            this.slideAdapter.setItemWidth(this.galleryItemWidth);
+                        }
+
+                    }
                 }
                 break;
             case "slidePosition":