/*
* Copyright (C) 2006 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.widget;
import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
/**
* {@link FrameLayout} 容器类的基类，用于在变换视图时显示动画效果.
*
* @attr ref android.R.styleable#ViewAnimator_inAnimation
* @attr ref android.R.styleable#ViewAnimator_outAnimation
* @attr ref android.R.styleable#ViewAnimator_animateFirstView
* @author translate by cnmahj
*/
public class ViewAnimator extends FrameLayout {
int mWhichChild = 0;
boolean mFirstTime = true;
boolean mAnimateFirstTime = true;
Animation mInAnimation;
Animation mOutAnimation;
public ViewAnimator(Context context) {
super(context);
initViewAnimator(context, null);
}
public ViewAnimator(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray a = context.obtainStyledAttributes(attrs, com.android.internal.R.styleable.ViewAnimator);
int resource = a.getResourceId(com.android.internal.R.styleable.ViewAnimator_inAnimation, 0);
if (resource > 0) {
setInAnimation(context, resource);
}
resource = a.getResourceId(com.android.internal.R.styleable.ViewAnimator_outAnimation, 0);
if (resource > 0) {
setOutAnimation(context, resource);
}
boolean flag = a.getBoolean(com.android.internal.R.styleable.ViewAnimator_animateFirstView, true);
setAnimateFirstView(flag);
a.recycle();
initViewAnimator(context, attrs);
}
/**
* Initialize this {@link ViewAnimator}, possibly setting
* {@link #setMeasureAllChildren(boolean)} based on {@link FrameLayout} flags.
*/
private void initViewAnimator(Context context, AttributeSet attrs) {
if (attrs == null) {
// For compatibility, always measure children when undefined.
mMeasureAllChildren = true;
return;
}
// For compatibility, default to measure children, but allow XML
// attribute to override.
final TypedArray a = context.obtainStyledAttributes(attrs,
com.android.internal.R.styleable.FrameLayout);
final boolean measureAllChildren = a.getBoolean(
com.android.internal.R.styleable.FrameLayout_measureAllChildren, true);
setMeasureAllChildren(measureAllChildren);
a.recycle();
}
/**
* 设置要显示的子视图.
*
* @param whichChild 要显示的子视图的索引.
*/
@android.view.RemotableViewMethod
public void setDisplayedChild(int whichChild) {
mWhichChild = whichChild;
if (whichChild >= getChildCount()) {
mWhichChild = 0;
} else if (whichChild < 0) {
mWhichChild = getChildCount() - 1;
}
boolean hasFocus = getFocusedChild() != null;
// This will clear old focus if we had it
showOnly(mWhichChild);
if (hasFocus) {
// Try to retake focus if we had it
requestFocus(FOCUS_FORWARD);
}
}
/**
* 返回当前显示的子视图的索引.
*/
public int getDisplayedChild() {
return mWhichChild;
}
/**
* 显示下一个视图.
*/
@android.view.RemotableViewMethod
public void showNext() {
setDisplayedChild(mWhichChild + 1);
}
/**
* 显示前一个视图.
*/
@android.view.RemotableViewMethod
public void showPrevious() {
setDisplayedChild(mWhichChild - 1);
}
/**
* Shows only the specified child. The other displays Views exit the screen,
* optionally with the with the {@link #getOutAnimation() out animation} and
* the specified child enters the screen, optionally with the
* {@link #getInAnimation() in animation}.
*
* @param childIndex The index of the child to be shown.
* @param animate Whether or not to use the in and out animations, defaults
* to true.
*/
void showOnly(int childIndex, boolean animate) {
final int count = getChildCount();
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (i == childIndex) {
if (animate && mInAnimation != null) {
child.startAnimation(mInAnimation);
}
child.setVisibility(View.VISIBLE);
mFirstTime = false;
} else {
if (animate && mOutAnimation != null && child.getVisibility() == View.VISIBLE) {
child.startAnimation(mOutAnimation);
} else if (child.getAnimation() == mInAnimation)
child.clearAnimation();
child.setVisibility(View.GONE);
}
}
}
/**
* Shows only the specified child. The other displays Views exit the screen
* with the {@link #getOutAnimation() out animation} and the specified child
* enters the screen with the {@link #getInAnimation() in animation}.
*
* @param childIndex The index of the child to be shown.
*/
void showOnly(int childIndex) {
final boolean animate = (!mFirstTime || mAnimateFirstTime);
showOnly(childIndex, animate);
}
@Override
public void addView(View child, int index, ViewGroup.LayoutParams params) {
super.addView(child, index, params);
if (getChildCount() == 1) {
child.setVisibility(View.VISIBLE);
} else {
child.setVisibility(View.GONE);
}
if (index >= 0 && mWhichChild >= index) {
// Added item above current one, increment the index of the displayed child
setDisplayedChild(mWhichChild + 1);
}
}
@Override
public void removeAllViews() {
super.removeAllViews();
mWhichChild = 0;
mFirstTime = true;
}
@Override
public void removeView(View view) {
final int index = indexOfChild(view);
if (index >= 0) {
removeViewAt(index);
}
}
@Override
public void removeViewAt(int index) {
super.removeViewAt(index);
final int childCount = getChildCount();
if (childCount == 0) {
mWhichChild = 0;
mFirstTime = true;
} else if (mWhichChild >= childCount) {
// Displayed is above child count, so float down to top of stack
setDisplayedChild(childCount - 1);
} else if (mWhichChild == index) {
// Displayed was removed, so show the new child living in its place
setDisplayedChild(mWhichChild);
}
}
public void removeViewInLayout(View view) {
removeView(view);
}
public void removeViews(int start, int count) {
super.removeViews(start, count);
if (getChildCount() == 0) {
mWhichChild = 0;
mFirstTime = true;
} else if (mWhichChild >= start && mWhichChild < start + count) {
// Try showing new displayed child, wrapping if needed
setDisplayedChild(mWhichChild);
}
}
public void removeViewsInLayout(int start, int count) {
removeViews(start, count);
}
/**
* 返回当前显示的子视图.
*
* @return 当前显示的子视图.
*
* @see #getDisplayedChild()
*/
public View getCurrentView() {
return getChildAt(mWhichChild);
}
/**
* 返回用于绘制视图进入屏幕时动画的动画对象.
*
* @return 动画对象；未设定时返回空.
*
* @see #setInAnimation(android.view.animation.Animation)
* @see #setInAnimation(android.content.Context, int)
*/
public Animation getInAnimation() {
return mInAnimation;
}
/**
* 设置用于绘制视图进入屏幕时动画的动画对象.
*
* @param inAnimation 视图进入屏幕时显示动画用的动画对象.
*
* @see #getInAnimation()
* @see #setInAnimation(android.content.Context, int)
*/
public void setInAnimation(Animation inAnimation) {
mInAnimation = inAnimation;
}
/**
* 返回用于绘制视图退出屏幕时动画的动画对象.
*
* @return 动画对象；未设定时返回空.
*
* @see #setOutAnimation(android.view.animation.Animation)
* @see #setOutAnimation(android.content.Context, int)
*/
public Animation getOutAnimation() {
return mOutAnimation;
}
/**
* 设置用于绘制视图退出屏幕时动画的动画对象.
*
* @param outAnimation 视图退出屏幕时显示动画用的动画对象.
*
* @see #getOutAnimation()
* @see #setOutAnimation(android.content.Context, int)
*/
public void setOutAnimation(Animation outAnimation) {
mOutAnimation = outAnimation;
}
/**
* 设置用于绘制视图进入屏幕时动画的动画对象.
*
* @param context 应用程序上下文.
* @param resourceID 动画对象的资源 ID.
*
* @see #getInAnimation()
* @see #setInAnimation(android.view.animation.Animation)
*/
public void setInAnimation(Context context, int resourceID) {
setInAnimation(AnimationUtils.loadAnimation(context, resourceID));
}
/**
* 设置用于绘制视图退出屏幕时动画的动画对象.
*
* @param context 应用程序上下文.
* @param resourceID 动画对象的资源 ID.
*
* @see #getOutAnimation()
* @see #setOutAnimation(android.view.animation.Animation)
*/
public void setOutAnimation(Context context, int resourceID) {
setOutAnimation(AnimationUtils.loadAnimation(context, resourceID));
}
/**
* Returns whether the current View should be animated the first time the ViewAnimator
* is displayed.
*
* @return true if the current View will be animated the first time it is displayed,
* false otherwise.
*
* @see #setAnimateFirstView(boolean)
*/
public boolean getAnimateFirstView() {
return mAnimateFirstTime;
}
/**
* 设置视图动画对象首次显示时，是否为当前视图显示动画.
*
* @param animate 视图动画对象首次显示时为当前视图显示动画时为真；否则为假.
*/
public void setAnimateFirstView(boolean animate) {
mAnimateFirstTime = animate;
}
@Override
public int getBaseline() {
return (getCurrentView() != null) ? getCurrentView().getBaseline() : super.getBaseline();
}
@Override
public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(event);
event.setClassName(ViewAnimator.class.getName());
}
@Override
public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
super.onInitializeAccessibilityNodeInfo(info);
info.setClassName(ViewAnimator.class.getName());
}
}