mvvm and candies

js-framework/src/util/candies.ts

@@ -0,0 +1,100 @@
+/*
+ * Copyright [2019] [Doric.Pub]
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { View, Stack, VLayout, HLayout } from "../ui/view"
+
+export type ViewBlock = () => View
+
+export function stack(blocks: ViewBlock[]) {
+    return takeAlso(new Stack)(
+        it => {
+            for (let block of blocks) {
+                it.addChild(block())
+            }
+        })
+}
+
+export function vlayout(blocks: ViewBlock[]) {
+    return takeAlso(new VLayout)(
+        it => {
+            for (let block of blocks) {
+                it.addChild(block())
+            }
+        })
+}
+
+export function hlayout(blocks: ViewBlock[]) {
+    return takeAlso(new HLayout)(
+        it => {
+            for (let block of blocks) {
+                it.addChild(block())
+            }
+        })
+}
+
+export function take<T>(target: T) {
+    return (block: (p: T) => void) => {
+        block(target)
+    }
+}
+
+export function takeNonNull<T, R>(target?: T) {
+    return (block: (p: T) => R) => {
+        if (target !== undefined) {
+            return block(target)
+        }
+    }
+}
+
+export function takeNull<T, R>(target?: T) {
+    return (block: () => R) => {
+        if (target === undefined) {
+            return block()
+        }
+    }
+}
+
+export function takeLet<T, R>(target: T) {
+    return (block: (p: T) => R | undefined) => {
+        return block(target)
+    }
+}
+
+export function takeAlso<T>(target: T) {
+    return (block: (p: T) => void) => {
+        block(target)
+        return target
+    }
+}
+
+export function takeIf<T>(target: T) {
+    return (predicate: (t: T) => boolean) => {
+        return predicate(target) ? target : undefined
+    }
+}
+
+export function takeUnless<T>(target: T) {
+    return (predicate: (t: T) => boolean) => {
+        return predicate(target) ? undefined : target
+    }
+}
+
+export function repeat(action: (count: number) => void) {
+    return (times: number) => {
+        for (let i = 0; i < times; i++) {
+            action(i)
+        }
+    }
+}