最近工作中总会涉及到Insets相关的一些内容，网上对于Insets的分析以及介绍还是较少的，这里对Insets涉及到一些概念和方法做一个总结。
什么是Insets？
WindowInsets 源码解释为 window content的一系列插值集合，（个人理解为 一个Activity相对于手机屏幕需要空出的地方以腾纳给statusbar、Ime、Navigationbar等系统窗口，具体表现为该区域需要的上下左右的宽高，比如输入法窗口的区域就是一个Inset）
WindowInsets包括三类：SystemWindowInsets、StableInsets、WIndowDecorInsets
- SystemWindowInsets：全窗口下，被navigationbar、statusbar、ime或其他系统窗口覆盖的区域
- StableInsets：全窗口下，被系统UI覆盖的区域
- WIndowDecorInsets：系统预留属性
Insets相关类
InsetsState
保存系统中所有的Insets的状态，他是状态描述者，持有系统中可以产生Window Insets的window状态 private InsetsSource[] mSources = new InsetsSource[SIZE]; // mSources变量维护所有产生Insets的window（也就是InsetsSource）的状态
它主要持有以下几种类型的Insets
ITYPE_STATUS_BAR, ITYPE_NAVIGATION_BAR, ITYPE_CAPTION_BAR, ITYPE_TOP_GESTURES, ITYPE_BOTTOM_GESTURES, ITYPE_LEFT_GESTURES, ITYPE_RIGHT_GESTURES, ITYPE_TOP_TAPPABLE_ELEMENT, ITYPE_BOTTOM_TAPPABLE_ELEMENT, ITYPE_LEFT_DISPLAY_CUTOUT, ITYPE_TOP_DISPLAY_CUTOUT, ITYPE_RIGHT_DISPLAY_CUTOUT, ITYPE_BOTTOM_DISPLAY_CUTOUT, ITYPE_IME, ITYPE_CLIMATE_BAR, ITYPE_EXTRA_NAVIGATION_BAR
如果InsetsState发生改变后，会通过MSG_INSETS_CHANGED消息发送到InsetsController，进行修改并保存到变量mState中
public boolean onStateChanged(InsetsState state) {
boolean stateChanged = !mState.equals(state, true /* excludingCaptionInsets */,false /* excludeInvisibleIme */) || !captionInsetsUnchanged();
if (!stateChanged && mLastDispatchedState.equals(state)) {
return false;
}
updateState(state);
boolean localStateChanged = !mState.equals(mLastDispatchedState,
true /* excludingCaptionInsets */, true /* excludeInvisibleIme */);
mLastDispatchedState.set(state, true /* copySources */);
applyLocalVisibilityOverride();
if (localStateChanged) {
if (DEBUG) Log.d(TAG, "onStateChanged, notifyInsetsChanged, send state to WM: " mState);
mHost.notifyInsetsChanged();
updateRequestedState();
}
return true;
}
InsetsState的关键方法：
WindowInsets calculateInsets（...）：基于当前source设置计算新的windowInsets void processSource（InsetsSource source，...）: 根据计算值更新source值
InsetsStateController
管理所有窗口的Insets的state
private final InsetsState mLastState = new InsetsState(); //旧的InsetsState private final InsetsState mState = new InsetsState(); //新的InsetsState
几个重要的方法：
private boolean isAboveIme(WindowContainer target）// 判断当前窗口是否处在输入法窗口层级上 void onImeControlTargetChanged(@Nullable InsetsControlTarget imeTarget) //当输入法target 窗口发生变化触发 InsetsState getInsetsForDispatch(@NonNull WindowState target) //分发Insets 对Insets进一步更新（更新frame 或者visible）
InsetsSource
是Insets产生者的描述，记录每一个产生Insets的window的状态，主要记录产生的Insets区域
private final @InternalInsetsType int mType; //Insets类型 nav或者status或者... private final Rect mFrame; //代表Insets区域 private boolean mVisible; //Insets可见性
/*几个重要的方法/
public void setFrame(Rect frame) //设置Insets大小 public void setVisible(boolean visible) //设置Insets可见性 private Insets calculateInsets(Rect relativeFrame, Rect frame, boolean ignoreVisibility) //根据frame以及ignoreVisibility 计算Insets
InsetsSourceConsumer（ImeInsetsSourceConsumer）
对单一InsetsSource的消费者，其内部持有InsetsSourceControl，可以控制其leash的可见性和动画，输入法有专门的ImeInsetsSourceConsumer来消费输入法的Insets
protected boolean mRequestedVisible; //单一Insets的可见性 private @Nullable InsetsSourceControl mSourceControl; // 持有InsetsSourceControl变量可以实现对单一InsetsSource的控制 protected final InsetsController mController; //所属的InsetController protected final InsetsState mState; //本地state
/几个重要的方法/
public void updateSource(InsetsSource newSource, @AnimationType int animationType) //更新mstate中的source 主要更新frame
public void show(boolean fromIme) //显示Insets
protected void setRequestedVisible(boolean requestedVisible) //设置Insets的可见性
public void setControl(@Nullable InsetsSourceControl control,
@InsetsType int[] showTypes, @InsetsType int[] hideTypes) //后面讲
public void hide() //隐藏Insets
boolean applyLocalVisibilityOverride() //主要更新state可见性
protected boolean isRequestedVisibleAwaitingControl() //判断当前Insets是否会在获得control时更新可见性，即判断是否存在pending show（如果是bars 该方法等同于isRequestedVisible）
ImeInsetsSourceConsumer
private boolean mIsRequestedVisibleAwaitingControl; //判断是否存在一个请求要让输入法显示出来（但是由于当前尚未获得control因此暂时无法实现这个操作） void notifyHidden() //控制IMM隐藏输入法 public @ShowResult int requestShow(boolean fromIme) //控制IMM显示输入法 public void removeSurface() //移除输入法的surface - InsetsSourceControl 对InsetsSource的控制者，用来控制Insets的产生者，内部持有控制输入法动画的Leash private final @InternalInsetsType int mType; //InsetsSource类型 private final @Nullable SurfaceControl mLeash; //播放动画需要的Leash ，app可以控制对其设置position实现位移动画 private final Point mSurfacePosition; //当前leash(Surface)在屏幕中的position - InsetsSourceProvider 他是特定InsetsSource在server端的控制者，他被称作provider是因为他提供InsetsSource给客户端（客户端通过InsetsSourceConsumer使用InsetsSource）
这里重点关注ImeInsetsSourceProvider
private InsetsControlTarget mImeTargetFromIme; //输入法Insets的control（Insets需要有一个control，否则他就会失控 不可控制） private Runnable mShowImeRunner; //显示输入法线程 private boolean mIsImeLayoutDrawn; //输入法是否已经绘制完成
InsetsController
它是WindowInsets在client端的实现 用来控制insets ，InsetsController只在ViewRootImpl里面创建的，每个Window会对应一个ViewRootImpl，同样每个ViewRootImpl会对应每个InsetsController
/*关键成员变量*/ InsetsState mState = new InsetsState(); //记录本地State （Client端的Insetsstate） InsetsState mLastDispatchedState = new InsetsState(); //从system端传来的InsetsState InsetsState mRequestedState = new InsetsState(); //发送给系统端的InsetsState SparseArray<InsetsSourceConsumer> mSourceConsumers = new SparseArray<>(); //持有sourceConsumers /*关键方法*/ public void applyImeVisibility(boolean setVisible) //更新输入法可见性 public void notifyFinished(InsetsAnimationControlRunner runner, boolean shown) //动画结束时回调方法 public void onControlsChanged(InsetsSourceControl[] activeControls) //当系统端分发新的Insets Controls时被调用 public boolean onStateChanged(InsetsState state) //Insets或者InsetsControl发生改变会调用 public void setSystemBarsBehavior(@Behavior int behavior) public void setSystemBarsAppearance(@Appearance int appearance, @Appearance int mask) //更改Systembar的表现行为 public void show(@InsetsType int types, boolean fromIme) //显示Insets void hide(@InsetsType int types, boolean fromIme) //隐藏Insets private void updateState(InsetsState newState) //更新state private void updateRequestedState() //如果Insets在client端发生改变再重新发送到server端 public void applyAnimation(@InsetsType final int types, boolean show, boolean fromIme) //更新Insets动画
InsetsChanged、InsetsControlChanged方法
Insets的变化一般是通过消息机制来进行更改的，主要是两方面的更改包括InsetsChanged和InsetsControlChanged，他们是由System_server经过WindowState调用到App进程的。
WindowState.java //属于Server端
void notifyInsetsChanged() {
ProtoLog.d(WM_DEBUG_IME, "notifyInsetsChanged for %s ", this);
try {
mClient.insetsChanged(getInsetsState());
} catch (RemoteException e) {
Slog.w(TAG, "Failed to deliver inset state change w=" this, e);
}
}
ViewRootImpl#W
@Override
public void insetsChanged(InsetsState insetsState) {
final ViewRootImpl viewAncestor = mViewAncestor.get();
if (viewAncestor != null) {
viewAncestor.dispatchInsetsChanged(insetsState);
}
}
@Override
public void insetsControlChanged(InsetsState insetsState,
InsetsSourceControl[] activeControls) {
final ViewRootImpl viewAncestor = mViewAncestor.get();
if (viewAncestor != null) {
viewAncestor.dispatchInsetsControlChanged(insetsState, activeControls);
}
}
异步发送消息：MSG_INSETS_CHANGED、MSG_INSETS_CONTROL_CHANGED
case MSG_INSETS_CHANGED:
mInsetsController.onStateChanged((InsetsState) msg.obj);
break;
case MSG_INSETS_CONTROL_CHANGED: {
mInsetsController.onStateChanged((InsetsState) args.arg1);
mInsetsController.onControlsChanged((InsetsSourceControl[]) args.arg2);
break; //首先都会调用InsetsController的onStateChanged方法
}
onStateChanged
public boolean onStateChanged(InsetsState state) {
boolean stateChanged = !mState.equals(state, true /* excludingCaptionInsets */,false /* excludeInvisibleIme */) //判断client端state和传来的state是否一致
|| !captionInsetsUnchanged();
//同时判断上次server端传来的state是否同当前传传来的state一致
if (!stateChanged && mLastDispatchedState.equals(state)) {
return false;
}
if (DEBUG) Log.d(TAG, "onStateChanged: " state);
updateState(state);
//判断client端本地state是否已经发生改变
boolean localStateChanged = !mState.equals(mLastDispatchedState,
true /* excludingCaptionInsets */, true /* excludeInvisibleIme */);
//更新mLastDispatchedState 即更新server端传来的state
mLastDispatchedState.set(state, true /* copySources */);
//将更新apply到本地
applyLocalVisibilityOverride();
if (localStateChanged) {
if (DEBUG) Log.d(TAG, "onStateChanged, notifyInsetsChanged, send state to WM: " mState);
//如果本地Insets发生改变了，通知server端Insets更改了
mHost.notifyInsetsChanged();
//更新传递给server端的InsetsState
updateRequestedState();
}
return true;
}
onControlsChanged
该方法在窗口获取焦点或者失去焦点的时候也会调用到
public void onControlsChanged(InsetsSourceControl[] activeControls) {
if (activeControls != null) {
for (InsetsSourceControl activeControl : activeControls) {
if (activeControl != null) {
// TODO(b/122982984): Figure out why it can be null.
mTmpControlArray.put(activeControl.getType(), activeControl);
}
}
}
boolean requestedStateStale = false;
final int[] showTypes = new int[1]; //系统Insets会根据showTypes数组内的值去更新可见性
final int[] hideTypes = new int[1];
//遍历所有的SourceConsumer 更新system_server传来的InsetsSourceControl
for (int i = mSourceConsumers.size() - 1; i >= 0; i--) {
final InsetsSourceConsumer consumer = mSourceConsumers.valueAt(i);
final InsetsSourceControl control = mTmpControlArray.get(consumer.getType());
consumer.setControl(control, showTypes, hideTypes);
}
// Ensure to create source consumers if not available yet.
//便利system_server传递来的InsetsSourceControl
for (int i = mTmpControlArray.size() - 1; i >= 0; i--) {
final InsetsSourceControl control = mTmpControlArray.valueAt(i);
final @InternalInsetsType int type = control.getType();
final InsetsSourceConsumer consumer = getSourceConsumer(type);
//如果consumer不存在会创建
consumer.setControl(control, showTypes, hideTypes); //可以看到如果存在対赢得consumer 会调用setControl方法两次
...
}
mTmpControlArray.clear();
//showTypes、hideTypes值会在setControl方法内进行修改
int animatingTypes = invokeControllableInsetsChangedListeners();
showTypes[0] &= ~animatingTypes;
hideTypes[0] &= ~animatingTypes;
//假设showTypes[0]=8 代表要显示输入法
if (showTypes[0] != 0) {
applyAnimation(showTypes[0], true /* show */, false /* fromIme */);
}
//假设hideTypes[0]=8 代表要隐藏输入法
if (hideTypes[0] != 0) {
applyAnimation(hideTypes[0], false /* show */, false /* fromIme */);
}
if (requestedStateStale) {
updateRequestedState();
}
}
总结
- 每个ViewRootImpl对应一个InsetsController实例，他是一个App进程中控制Insets的核心类，用于保存传递系统中产生Insets的window的状态和动画需要的leash以及控制播放动画
- InsetsSource是对产生Insets的窗口的状态描述，包括可见性以及Insets的大小
- 每个InsetsController会持有一个成员变量mState（InsetsState），它保存了系统中所有产生Insets的Window（InsetsSource）的状态列表，状态主要是指可见性以及产生Insets的window的区域大小
- InsetsSourceConsumer 是用来消费特定InsetsSource，消费主要是指对产生Insets 的window即InsetsSource进行可见性控制以及播放动画，通过持有的window的Leash来实现，也就是mSourceControl（InsetsSourceControl）
- 每个InsetsController会持有多个InsetsSourceConsumer，他持有一个InsetsSourceConsumers列表，SparseArray mSourceConsumers
到这里Insets已经总结完毕，后续将进一步通过源码分析Insets的原理以及和App之间的关系，由于水平有限，难免有错误，若在阅读时发现不妥或者错误的地方留言指正，共同进步，谢谢!
Have a nice day!
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