1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.contacts.util; 18 19 import android.view.View; 20 import android.view.ViewTreeObserver.OnDrawListener; 21 import android.view.ViewTreeObserver.OnGlobalLayoutListener; 22 import android.view.ViewTreeObserver.OnPreDrawListener; 23 24 /** Static methods that are useful for scheduling actions to occur at a later time. */ 25 public class SchedulingUtils { 26 27 28 /** Runs a piece of code after the next layout run */ doAfterLayout(final View view, final Runnable runnable)29 public static void doAfterLayout(final View view, final Runnable runnable) { 30 final OnGlobalLayoutListener listener = new OnGlobalLayoutListener() { 31 @Override 32 public void onGlobalLayout() { 33 // Layout pass done, unregister for further events 34 view.getViewTreeObserver().removeOnGlobalLayoutListener(this); 35 runnable.run(); 36 } 37 }; 38 view.getViewTreeObserver().addOnGlobalLayoutListener(listener); 39 } 40 41 /** Runs a piece of code just before the next draw, after layout and measurement */ doOnPreDraw(final View view, final boolean drawNextFrame, final Runnable runnable)42 public static void doOnPreDraw(final View view, final boolean drawNextFrame, 43 final Runnable runnable) { 44 final OnPreDrawListener listener = new OnPreDrawListener() { 45 @Override 46 public boolean onPreDraw() { 47 view.getViewTreeObserver().removeOnPreDrawListener(this); 48 runnable.run(); 49 return drawNextFrame; 50 } 51 }; 52 view.getViewTreeObserver().addOnPreDrawListener(listener); 53 } 54 } 55