Java tutorial
/* * Copyright (C) 2014 The Android Open Source Project * * 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. */ package android.transition; import android.animation.Animator; import android.animation.TimeInterpolator; import android.content.Context; import android.graphics.Rect; import android.util.AttributeSet; import android.view.View; import android.view.ViewGroup; import android.view.animation.AccelerateInterpolator; import android.view.animation.DecelerateInterpolator; import com.android.internal.R; /** * This transition tracks changes to the visibility of target views in the * start and end scenes and moves views in or out from the edges of the * scene. Visibility is determined by both the * {@link View#setVisibility(int)} state of the view as well as whether it * is parented in the current view hierarchy. Disappearing Views are * limited as described in {@link Visibility#onDisappear(android.view.ViewGroup, * TransitionValues, int, TransitionValues, int)}. * <p>Views move away from the focal View or the center of the Scene if * no epicenter was provided.</p> */ public class Explode extends Visibility { private static final TimeInterpolator sDecelerate = new DecelerateInterpolator(); private static final TimeInterpolator sAccelerate = new AccelerateInterpolator(); private static final String TAG = "Explode"; private static final String PROPNAME_SCREEN_BOUNDS = "android:explode:screenBounds"; private int[] mTempLoc = new int[2]; public Explode() { setPropagation(new CircularPropagation()); } public Explode(Context context, AttributeSet attrs) { super(context, attrs); setPropagation(new CircularPropagation()); } private void captureValues(TransitionValues transitionValues) { View view = transitionValues.view; view.getLocationOnScreen(mTempLoc); int left = mTempLoc[0]; int top = mTempLoc[1]; int right = left + view.getWidth(); int bottom = top + view.getHeight(); transitionValues.values.put(PROPNAME_SCREEN_BOUNDS, new Rect(left, top, right, bottom)); } @Override public void captureStartValues(TransitionValues transitionValues) { super.captureStartValues(transitionValues); captureValues(transitionValues); } @Override public void captureEndValues(TransitionValues transitionValues) { super.captureEndValues(transitionValues); captureValues(transitionValues); } @Override public Animator onAppear(ViewGroup sceneRoot, View view, TransitionValues startValues, TransitionValues endValues) { if (endValues == null) { return null; } Rect bounds = (Rect) endValues.values.get(PROPNAME_SCREEN_BOUNDS); float endX = view.getTranslationX(); float endY = view.getTranslationY(); calculateOut(sceneRoot, bounds, mTempLoc); float startX = endX + mTempLoc[0]; float startY = endY + mTempLoc[1]; return TranslationAnimationCreator.createAnimation(view, endValues, bounds.left, bounds.top, startX, startY, endX, endY, sDecelerate, this); } @Override public Animator onDisappear(ViewGroup sceneRoot, View view, TransitionValues startValues, TransitionValues endValues) { if (startValues == null) { return null; } Rect bounds = (Rect) startValues.values.get(PROPNAME_SCREEN_BOUNDS); int viewPosX = bounds.left; int viewPosY = bounds.top; float startX = view.getTranslationX(); float startY = view.getTranslationY(); float endX = startX; float endY = startY; int[] interruptedPosition = (int[]) startValues.view.getTag(R.id.transitionPosition); if (interruptedPosition != null) { // We want to have the end position relative to the interrupted position, not // the position it was supposed to start at. endX += interruptedPosition[0] - bounds.left; endY += interruptedPosition[1] - bounds.top; bounds.offsetTo(interruptedPosition[0], interruptedPosition[1]); } calculateOut(sceneRoot, bounds, mTempLoc); endX += mTempLoc[0]; endY += mTempLoc[1]; return TranslationAnimationCreator.createAnimation(view, startValues, viewPosX, viewPosY, startX, startY, endX, endY, sAccelerate, this); } private void calculateOut(View sceneRoot, Rect bounds, int[] outVector) { sceneRoot.getLocationOnScreen(mTempLoc); int sceneRootX = mTempLoc[0]; int sceneRootY = mTempLoc[1]; int focalX; int focalY; Rect epicenter = getEpicenter(); if (epicenter == null) { focalX = sceneRootX + (sceneRoot.getWidth() / 2) + Math.round(sceneRoot.getTranslationX()); focalY = sceneRootY + (sceneRoot.getHeight() / 2) + Math.round(sceneRoot.getTranslationY()); } else { focalX = epicenter.centerX(); focalY = epicenter.centerY(); } int centerX = bounds.centerX(); int centerY = bounds.centerY(); double xVector = centerX - focalX; double yVector = centerY - focalY; if (xVector == 0 && yVector == 0) { // Random direction when View is centered on focal View. xVector = (Math.random() * 2) - 1; yVector = (Math.random() * 2) - 1; } double vectorSize = Math.hypot(xVector, yVector); xVector /= vectorSize; yVector /= vectorSize; double maxDistance = calculateMaxDistance(sceneRoot, focalX - sceneRootX, focalY - sceneRootY); outVector[0] = (int) Math.round(maxDistance * xVector); outVector[1] = (int) Math.round(maxDistance * yVector); } private static double calculateMaxDistance(View sceneRoot, int focalX, int focalY) { int maxX = Math.max(focalX, sceneRoot.getWidth() - focalX); int maxY = Math.max(focalY, sceneRoot.getHeight() - focalY); return Math.hypot(maxX, maxY); } }