窗口分类
总的来说，我们接触到的所有的视图基本都分为window和view两大类。window是view的载体，view是window的具体表现。
xxview:各种继承自View的对象，如TextView、LinearLayout等。
remoteViews：桌面小挂件等。
应用窗口：Dialog，Activity等。
子窗口：popupWindow等。
系统窗口：状态栏，通知栏，导航栏，toast，输入法等。
public static class LayoutParams extends ViewGroup.LayoutParams
implements Parcelable {
//窗口的绝对XY位置，需要考虑gravity属性
public int x;
public int y;
//在横纵方向上为相关的View预留多少扩展像素，如果是0则此view不能被拉伸，其他情况下扩展像素被widget均分
public float horizontalWeight;
public float verticalWeight;
//窗口类型
//有3种主要类型如下：
//ApplicationWindows取值在FIRST_APPLICATION_WINDOW与LAST_APPLICATION_WINDOW之间，是常用的顶层应用程序窗口，须将token设置成Activity的token；
//SubWindows取值在FIRST_SUB_WINDOW和LAST_SUB_WINDOW之间，与顶层窗口相关联，需将token设置成它所附着宿主窗口的token；
//SystemWindows取值在FIRST_SYSTEM_WINDOW和LAST_SYSTEM_WINDOW之间，不能用于应用程序，使用时需要有特殊权限，它是特定的系统功能才能使用；
public int type;
//WindowType：开始应用程序窗口
public static final int FIRST_APPLICATION_WINDOW = 1;
//WindowType：所有程序窗口的base窗口，其他应用程序窗口都显示在它上面
public static final int TYPE_BASE_APPLICATION = 1;
//WindowType：普通应用程序窗口，token必须设置为Activity的token来指定窗口属于谁
public static final int TYPE_APPLICATION = 2;
//WindowType：应用程序启动时所显示的窗口，应用自己不要使用这种类型，它被系统用来显示一些信息，直到应用程序可以开启自己的窗口为止
public static final int TYPE_APPLICATION_STARTING = 3;
//WindowType：结束应用程序窗口
public static final int LAST_APPLICATION_WINDOW = 99;
//WindowType：SubWindows子窗口，子窗口的Z序和坐标空间都依赖于他们的宿主窗口
public static final int FIRST_SUB_WINDOW = 1000;
//WindowType： 面板窗口，显示于宿主窗口的上层
public static final int TYPE_APPLICATION_PANEL = FIRST_SUB_WINDOW;
//WindowType：媒体窗口（例如视频），显示于宿主窗口下层
public static final int TYPE_APPLICATION_MEDIA = FIRST_SUB_WINDOW+1;
//WindowType：应用程序窗口的子面板，显示于所有面板窗口的上层
public static final int TYPE_APPLICATION_SUB_PANEL = FIRST_SUB_WINDOW+2;
//WindowType：对话框，类似于面板窗口，绘制类似于顶层窗口，而不是宿主的子窗口
public static final int TYPE_APPLICATION_ATTACHED_DIALOG = FIRST_SUB_WINDOW+3;
//WindowType：媒体信息，显示在媒体层和程序窗口之间，需要实现半透明效果
public static final int TYPE_APPLICATION_MEDIA_OVERLAY = FIRST_SUB_WINDOW+4;
//WindowType：子窗口结束
public static final int LAST_SUB_WINDOW = 1999;
//WindowType：系统窗口，非应用程序创建
public static final int FIRST_SYSTEM_WINDOW = 2000;
//WindowType：状态栏，只能有一个状态栏，位于屏幕顶端，其他窗口都位于它下方
public static final int TYPE_STATUS_BAR = FIRST_SYSTEM_WINDOW;
//WindowType：搜索栏，只能有一个搜索栏，位于屏幕上方
public static final int TYPE_SEARCH_BAR = FIRST_SYSTEM_WINDOW+1;
//WindowType：电话窗口，它用于电话交互（特别是呼入），置于所有应用程序之上，状态栏之下
public static final int TYPE_PHONE = FIRST_SYSTEM_WINDOW+2;
//WindowType：系统提示，出现在应用程序窗口之上
public static final int TYPE_SYSTEM_ALERT = FIRST_SYSTEM_WINDOW+3;
//WindowType：锁屏窗口
public static final int TYPE_KEYGUARD = FIRST_SYSTEM_WINDOW+4;
//WindowType：信息窗口，用于显示Toast
public static final int TYPE_TOAST = FIRST_SYSTEM_WINDOW+5;
//WindowType：系统顶层窗口，显示在其他一切内容之上，此窗口不能获得输入焦点，否则影响锁屏
public static final int TYPE_SYSTEM_OVERLAY = FIRST_SYSTEM_WINDOW+6;
//WindowType：电话优先，当锁屏时显示，此窗口不能获得输入焦点，否则影响锁屏
public static final int TYPE_PRIORITY_PHONE = FIRST_SYSTEM_WINDOW+7;
//WindowType：系统对话框
public static final int TYPE_SYSTEM_DIALOG = FIRST_SYSTEM_WINDOW+8;
//WindowType：锁屏时显示的对话框
public static final int TYPE_KEYGUARD_DIALOG = FIRST_SYSTEM_WINDOW+9;
//WindowType：系统内部错误提示，显示于所有内容之上
public static final int TYPE_SYSTEM_ERROR = FIRST_SYSTEM_WINDOW+10;
//WindowType：内部输入法窗口，显示于普通UI之上，应用程序可重新布局以免被此窗口覆盖
public static final int TYPE_INPUT_METHOD = FIRST_SYSTEM_WINDOW+11;
//WindowType：内部输入法对话框，显示于当前输入法窗口之上
public static final int TYPE_INPUT_METHOD_DIALOG= FIRST_SYSTEM_WINDOW+12;
//WindowType：墙纸窗口
public static final int TYPE_WALLPAPER = FIRST_SYSTEM_WINDOW+13;
//WindowType：状态栏的滑动面板
public static final int TYPE_STATUS_BAR_PANEL = FIRST_SYSTEM_WINDOW+14;
//WindowType：安全系统覆盖窗口，这些窗户必须不带输入焦点，否则会干扰键盘
public static final int TYPE_SECURE_SYSTEM_OVERLAY = FIRST_SYSTEM_WINDOW+15;
//WindowType：拖放伪窗口，只有一个阻力层(最多)，它被放置在所有其他窗口上面
public static final int TYPE_DRAG = FIRST_SYSTEM_WINDOW+16;
//WindowType：状态栏下拉面板
public static final int TYPE_STATUS_BAR_SUB_PANEL = FIRST_SYSTEM_WINDOW+17;
//WindowType：鼠标指针
public static final int TYPE_POINTER = FIRST_SYSTEM_WINDOW+18;
//WindowType：导航栏(有别于状态栏时)
public static final int TYPE_NAVIGATION_BAR = FIRST_SYSTEM_WINDOW+19;
//WindowType：音量级别的覆盖对话框，显示当用户更改系统音量大小
public static final int TYPE_VOLUME_OVERLAY = FIRST_SYSTEM_WINDOW+20;
//WindowType：起机进度框，在一切之上
public static final int TYPE_BOOT_PROGRESS = FIRST_SYSTEM_WINDOW+21;
//WindowType：假窗，消费导航栏隐藏时触摸事件
public static final int TYPE_HIDDEN_NAV_CONSUMER = FIRST_SYSTEM_WINDOW+22;
//WindowType：梦想(屏保)窗口，略高于键盘
public static final int TYPE_DREAM = FIRST_SYSTEM_WINDOW+23;
//WindowType：导航栏面板(不同于状态栏的导航栏)
public static final int TYPE_NAVIGATION_BAR_PANEL = FIRST_SYSTEM_WINDOW+24;
//WindowType：universe背后真正的窗户
public static final int TYPE_UNIVERSE_BACKGROUND = FIRST_SYSTEM_WINDOW+25;
//WindowType：显示窗口覆盖，用于模拟辅助显示设备
public static final int TYPE_DISPLAY_OVERLAY = FIRST_SYSTEM_WINDOW+26;
//WindowType：放大窗口覆盖，用于突出显示的放大部分可访问性放大时启用
public static final int TYPE_MAGNIFICATION_OVERLAY = FIRST_SYSTEM_WINDOW+27;
//WindowType：......
public static final int TYPE_KEYGUARD_SCRIM = FIRST_SYSTEM_WINDOW+29;
public static final int TYPE_PRIVATE_PRESENTATION = FIRST_SYSTEM_WINDOW+30;
public static final int TYPE_VOICE_INTERACTION = FIRST_SYSTEM_WINDOW+31;
public static final int TYPE_ACCESSIBILITY_OVERLAY = FIRST_SYSTEM_WINDOW+32;
//WindowType：系统窗口结束
public static final int LAST_SYSTEM_WINDOW = 2999;
//MemoryType：窗口缓冲位于主内存
public static final int MEMORY_TYPE_NORMAL = 0;
//MemoryType：窗口缓冲位于可以被DMA访问，或者硬件加速的内存区域
public static final int MEMORY_TYPE_HARDWARE = 1;
//MemoryType：窗口缓冲位于可被图形加速器访问的区域
public static final int MEMORY_TYPE_GPU = 2;
//MemoryType：窗口缓冲不拥有自己的缓冲区，不能被锁定，缓冲区由本地方法提供
public static final int MEMORY_TYPE_PUSH_BUFFERS = 3;
//指出窗口所使用的内存缓冲类型，默认为NORMAL
public int memoryType;
//Flag：当该window对用户可见的时候，允许锁屏
public static final int FLAG_ALLOW_LOCK_WHILE_SCREEN_ON = 0x00000001;
//Flag：让该window后所有的东西都成暗淡
public static final int FLAG_DIM_BEHIND = 0x00000002;
//Flag：让该window后所有东西都模糊（4.0以上已经放弃这种毛玻璃效果）
public static final int FLAG_BLUR_BEHIND = 0x00000004;
//Flag：让window不能获得焦点，这样用户快就不能向该window发送按键事
public static final int FLAG_NOT_FOCUSABLE = 0x00000008;
//Flag：让该window不接受触摸屏事件
public static final int FLAG_NOT_TOUCHABLE = 0x00000010;
//Flag：即使在该window在可获得焦点情况下，依旧把该window之外的任何event发送到该window之后的其他window
public static final int FLAG_NOT_TOUCH_MODAL = 0x00000020;
//Flag：当手机处于睡眠状态时，如果屏幕被按下，那么该window将第一个收到
public static final int FLAG_TOUCHABLE_WHEN_WAKING = 0x00000040;
//Flag：当该window对用户可见时，让设备屏幕处于高亮（bright）状态
public static final int FLAG_KEEP_SCREEN_ON = 0x00000080;
//Flag：让window占满整个手机屏幕，不留任何边界
public static final int FLAG_LAYOUT_IN_SCREEN = 0x00000100;
//Flag：window大小不再不受手机屏幕大小限制，即window可能超出屏幕之外
public static final int FLAG_LAYOUT_NO_LIMITS = 0x00000200;
//Flag：window全屏显示
public static final int FLAG_FULLSCREEN = 0x00000400;
//Flag：恢复window非全屏显示
public static final int FLAG_FORCE_NOT_FULLSCREEN = 0x00000800;
//Flag：开启抖动（dithering）
public static final int FLAG_DITHER = 0x00001000;
//Flag：当该window在进行显示的时候，不允许截屏
public static final int FLAG_SECURE = 0x00002000;
//Flag：一个特殊模式的布局参数用于执行扩展表面合成时到屏幕上
public static final int FLAG_SCALED = 0x00004000;
//Flag：用于windows时,经常会使用屏幕用户持有反对他们的脸,它将积极过滤事件流,以防止意外按在这种情况下,可能不需要为特定的窗口,在检测到这样一个事件流时,应用程序将接收取消运动事件表明,这样应用程序可以处理这相应地采取任何行动的事件,直到手指释放
public static final int FLAG_IGNORE_CHEEK_PRESSES = 0x00008000;
//Flag：一个特殊的选项只用于结合FLAG_LAYOUT_IN_SC
public static final int FLAG_LAYOUT_INSET_DECOR = 0x00010000;
//Flag：转化的状态FLAG_NOT_FOCUSABLE对这个窗口当前如何进行交互的方法
public static final int FLAG_ALT_FOCUSABLE_IM = 0x00020000;
//Flag：如果你设置了该flag,那么在你FLAG_NOT_TOUNCH_MODAL的情况下，即使触摸屏事件发送在该window之外，其事件被发送到了后面的window,那么该window仍然将以MotionEvent.ACTION_OUTSIDE形式收到该触摸屏事件
public static final int FLAG_WATCH_OUTSIDE_TOUCH = 0x00040000;
//Flag：当锁屏的时候，显示该window
public static final int FLAG_SHOW_WHEN_LOCKED = 0x00080000;
//Flag：在该window后显示系统的墙纸
public static final int FLAG_SHOW_WALLPAPER = 0x00100000;
//Flag：当window被显示的时候，系统将把它当做一个用户活动事件，以点亮手机屏幕
public static final int FLAG_TURN_SCREEN_ON = 0x00200000;
//Flag：消失键盘
public static final int FLAG_DISMISS_KEYGUARD = 0x00400000;
//Flag：当该window在可以接受触摸屏情况下，让因在该window之外，而发送到后面的window的触摸屏可以支持split touch
public static final int FLAG_SPLIT_TOUCH = 0x00800000;
//Flag：对该window进行硬件加速，该flag必须在Activity或Dialog的Content View之前进行设置
public static final int FLAG_HARDWARE_ACCELERATED = 0x01000000;
//Flag：让window占满整个手机屏幕，不留任何边界
public static final int FLAG_LAYOUT_IN_OVERSCAN = 0x02000000;
//Flag：请求一个半透明的状态栏背景以最小的系统提供保护
public static final int FLAG_TRANSLUCENT_STATUS = 0x04000000;
//Flag：请求一个半透明的导航栏背景以最小的系统提供保护
public static final int FLAG_TRANSLUCENT_NAVIGATION = 0x08000000;
//Flag：......
public static final int FLAG_LOCAL_FOCUS_MODE = 0x10000000;
public static final int FLAG_SLIPPERY = 0x20000000;
public static final int FLAG_LAYOUT_ATTACHED_IN_DECOR = 0x40000000;
public static final int FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS = 0x80000000;
//行为选项标记
public int flags;
//PrivateFlags：......
public static final int PRIVATE_FLAG_FAKE_HARDWARE_ACCELERATED = 0x00000001;
public static final int PRIVATE_FLAG_FORCE_HARDWARE_ACCELERATED = 0x00000002;
public static final int PRIVATE_FLAG_WANTS_OFFSET_NOTIFICATIONS = 0x00000004;
public static final int PRIVATE_FLAG_SHOW_FOR_ALL_USERS = 0x00000010;
public static final int PRIVATE_FLAG_NO_MOVE_ANIMATION = 0x00000040;
public static final int PRIVATE_FLAG_COMPATIBLE_WINDOW = 0x00000080;
public static final int PRIVATE_FLAG_SYSTEM_ERROR = 0x00000100;
public static final int PRIVATE_FLAG_INHERIT_TRANSLUCENT_DECOR = 0x00000200;
public static final int PRIVATE_FLAG_KEYGUARD = 0x00000400;
public static final int PRIVATE_FLAG_DISABLE_WALLPAPER_TOUCH_EVENTS = 0x00000800;
//私有的行为选项标记
public int privateFlags;
public static final int NEEDS_MENU_UNSET = 0;
public static final int NEEDS_MENU_SET_TRUE = 1;
public static final int NEEDS_MENU_SET_FALSE = 2;
public int needsMenuKey = NEEDS_MENU_UNSET;
public static boolean mayUseInputMethod(int flags) {
......
}
//SOFT_INPUT：用于描述软键盘显示规则的bite的mask
public static final int SOFT_INPUT_MASK_STATE = 0x0f;
//SOFT_INPUT：没有软键盘显示的约定规则
public static final int SOFT_INPUT_STATE_UNSPECIFIED = 0;
//SOFT_INPUT：可见性状态softInputMode，请不要改变软输入区域的状态
public static final int SOFT_INPUT_STATE_UNCHANGED = 1;
//SOFT_INPUT：用户导航（navigate）到你的窗口时隐藏软键盘
public static final int SOFT_INPUT_STATE_HIDDEN = 2;
//SOFT_INPUT：总是隐藏软键盘
public static final int SOFT_INPUT_STATE_ALWAYS_HIDDEN = 3;
//SOFT_INPUT：用户导航（navigate）到你的窗口时显示软键盘
public static final int SOFT_INPUT_STATE_VISIBLE = 4;
//SOFT_INPUT：总是显示软键盘
public static final int SOFT_INPUT_STATE_ALWAYS_VISIBLE = 5;
//SOFT_INPUT：显示软键盘时用于表示window调整方式的bite的mask
public static final int SOFT_INPUT_MASK_ADJUST = 0xf0;
//SOFT_INPUT：不指定显示软件盘时，window的调整方式
public static final int SOFT_INPUT_ADJUST_UNSPECIFIED = 0x00;
//SOFT_INPUT：当显示软键盘时，调整window内的控件大小以便显示软键盘
public static final int SOFT_INPUT_ADJUST_RESIZE = 0x10;
//SOFT_INPUT：当显示软键盘时，调整window的空白区域来显示软键盘，即使调整空白区域，软键盘还是有可能遮挡一些有内容区域，这时用户就只有退出软键盘才能看到这些被遮挡区域并进行
public static final int SOFT_INPUT_ADJUST_PAN = 0x20;
//SOFT_INPUT：当显示软键盘时，不调整window的布局
public static final int SOFT_INPUT_ADJUST_NOTHING = 0x30;
//SOFT_INPUT：用户导航（navigate）到了你的window
public static final int SOFT_INPUT_IS_FORWARD_NAVIGATION = 0x100;
//软输入法模式选项
public int softInputMode;
//窗口如何停靠
public int gravity;
//水平边距，容器与widget之间的距离，占容器宽度的百分率
public float horizontalMargin;
//纵向边距
public float verticalMargin;
//积极的insets绘图表面和窗口之间的内容
public final Rect surfaceInsets = new Rect();
//期望的位图格式，默认为不透明，参考android.graphics.PixelFormat
public int format;
//窗口所使用的动画设置，它必须是一个系统资源而不是应用程序资源，因为窗口管理器不能访问应用程序
public int windowAnimations;
//整个窗口的半透明值，1.0表示不透明，0.0表示全透明
public float alpha = 1.0f;
//当FLAG_DIM_BEHIND设置后生效，该变量指示后面的窗口变暗的程度，1.0表示完全不透明，0.0表示没有变暗
public float dimAmount = 1.0f;
public static final float BRIGHTNESS_OVERRIDE_NONE = -1.0f;
public static final float BRIGHTNESS_OVERRIDE_OFF = 0.0f;
public static final float BRIGHTNESS_OVERRIDE_FULL = 1.0f;
public float screenBrightness = BRIGHTNESS_OVERRIDE_NONE;
//用来覆盖用户设置的屏幕亮度，表示应用用户设置的屏幕亮度，从0到1调整亮度从暗到最亮发生变化
public float buttonBrightness = BRIGHTNESS_OVERRIDE_NONE;
public static final int ROTATION_ANIMATION_ROTATE = 0;
public static final int ROTATION_ANIMATION_CROSSFADE = 1;
public static final int ROTATION_ANIMATION_JUMPCUT = 2;
//定义出入境动画在这个窗口旋转设备时使用
public int rotationAnimation = ROTATION_ANIMATION_ROTATE;
//窗口的标示符
public IBinder token = null;
//此窗口所在的包名
public String packageName = null;
//屏幕方向
public int screenOrientation = ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
//首选的刷新率的窗口
public float preferredRefreshRate;
//控制status bar是否显示
public int systemUiVisibility;
//ui能见度所请求的视图层次结构
public int subtreeSystemUiVisibility;
//得到关于系统ui能见度变化的回调
public boolean hasSystemUiListeners;
public static final int INPUT_FEATURE_DISABLE_POINTER_GESTURES = 0x00000001;
public static final int INPUT_FEATURE_NO_INPUT_CHANNEL = 0x00000002;
public static final int INPUT_FEATURE_DISABLE_USER_ACTIVITY = 0x00000004;
public int inputFeatures;
public long userActivityTimeout = -1;
......
public final int copyFrom(LayoutParams o) {
......
}
......
public void scale(float scale) {
......
}
......
}
Activity、View与Window的关系
image.png
View:窗口内的具体显示内容，能够处理触摸事件与绘制，View树的组成部分，由ViewRootImpl管理。
Window:对应一个View树、一块Surface和一个负责管理这个View树的ViewRootImpl对象，由WMS管理其窗口的大小、位置及触摸事件分发，SurfaceFlinger负责具体的绘制实现。
Activity:对开发人员来说就是一个窗口，对应一个PhoneWindow。
window存在的意义？
对于系统来说，它只需要知道window的大小和位置，而不关心window内具体的view，view树中各个view的具体展示和触摸事件的处理交由每个进程View树各自对应的ViewRootImpl处理。
image.png
activity存在的意义？
activity的本质就是一个界面，是系统对于一个window的封装，自己处理了activity堆栈的管理，并提供了丰富的回调去管理Activity的生命周期及其展示，而不需要与具体的window打交道。
窗口的添加过程
悬浮窗的添加过程
windowManager = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
layoutParams = new WindowManager.LayoutParams();
layoutParams.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT;
layoutParams.flags |= WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL;
layoutParams.gravity = Gravity.LEFT | Gravity.TOP; // 调整悬浮窗口至左上角
// 以屏幕左上角为原点，设置x、y初始值
layoutParams.x = 0;
layoutParams.y = 0;
// 设置悬浮窗口长宽数据
layoutParams.width = (int) (windowManager.getDefaultDisplay().getWidth() * 0.75);
layoutParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
layoutParams.format = 1;
layoutParams.alpha = 1F;
floatingOnTouchListener = new FloatingOnTouchListener();
pickOnTouchListener = new PickOnTouchListener();
root.setOnTouchListener(floatingOnTouchListener);
windowManager.addView(root, layoutParams);
windowManager = (WindowManager) getSystemService(Context.WINDOW_SERVICE);此处最终拿到了WindowManagerImpl对象。
registerService(Context.WINDOW_SERVICE, WindowManager.class,
new CachedServiceFetcher() {
@Override
public WindowManager createService(ContextImpl ctx) {
return new WindowManagerImpl(ctx);
}});
windowManager.addView(root, layoutParams);此处最终调用到了全局唯一的android.view.WindowManagerGlobal对象的addView方法.mGlobal是个单例。
public void addView(@NonNull View view, @NonNull ViewGroup.LayoutParams params) {
applyDefaultToken(params);
mGlobal.addView(view, params, mDisplay, mParentWindow);
}
而在android.view.WindowManagerGlobal#addView中会为每个窗口创建一个ViewRootImpl对象，并将需要其与待添加的窗口和属性记录到集合中。
public void addView(View view, ViewGroup.LayoutParams params,
private final ArrayList mViews = new ArrayList();
@UnsupportedAppUsage
private final ArrayList mRoots = new ArrayList();
@UnsupportedAppUsage
private final ArrayList mParams =
new ArrayList();
...
public void addView(View view, ViewGroup.LayoutParams params,Display display, Window parentWindow) {
final WindowManager.LayoutParams wparams = (WindowManager.LayoutParams) params;
if (parentWindow != null) {
parentWindow.adjustLayoutParamsForSubWindow(wparams);
} else {
// If there's no parent, then hardware acceleration for this view is
// set from the application's hardware acceleration setting.
final Context context = view.getContext();
if (context != null
&& (context.getApplicationInfo().flags
& ApplicationInfo.FLAG_HARDWARE_ACCELERATED) != 0) {
wparams.flags |= WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED;
}
}
ViewRootImpl root;
View panelParentView = null;
synchronized (mLock) {
//...
root = new ViewRootImpl(view.getContext(), display);
view.setLayoutParams(wparams);
mViews.add(view);
mRoots.add(root);
mParams.add(wparams);
}
// do this last because it fires off messages to start doing things
try {
root.setView(view, wparams, panelParentView);
} catch (RuntimeException e) {
//...
}
}
android.view.WindowManagerGlobal#addView最终调用到android.view.ViewRootImpl#setView方法中，并通过IWindowSession#addToDisplay的binder最终调用到WMS。
public void setView(View view, WindowManager.LayoutParams attrs, View panelParentView) {
synchronized (this) {
if (mView == null) {
mView = view;
...
//关键点1
// Schedule the first layout -before- adding to the window
// manager, to make sure we do the relayout before receiving
// any other events from the system.
requestLayout();
if ((mWindowAttributes.inputFeatures
& WindowManager.LayoutParams.INPUT_FEATURE_NO_INPUT_CHANNEL) == 0) {
mInputChannel = new InputChannel();
}
try {
//关键点2
res = mWindowSession.addToDisplay(mWindow, mSeq, mWindowAttributes,
getHostVisibility(), mDisplay.getDisplayId(),
mAttachInfo.mContentInsets, mAttachInfo.mStableInsets,
mAttachInfo.mOutsets, mInputChannel);
} catch (RemoteException e) {
...
}
}
final class Session extends IWindowSession.Stub
implements IBinder.DeathRecipient {
//...
@Override
public int addToDisplay(IWindow window, int seq, WindowManager.LayoutParams attrs,
int viewVisibility, int displayId, Rect outContentInsets, Rect outStableInsets,
Rect outOutsets, InputChannel outInputChannel) {
return mService.addWindow(this, window, seq, attrs, viewVisibility, displayId,
outContentInsets, outStableInsets, outOutsets, outInputChannel);
}
}
public int addWindow(Session session, IWindow client, int seq,
WindowManager.LayoutParams attrs, int viewVisibility, int displayId,
Rect outContentInsets, Rect outStableInsets, Rect outOutsets,
InputChannel outInputChannel) {
...
synchronized(mWindowMap) {
...
//关键点1 不能重复添加
if (mWindowMap.containsKey(client.asBinder())) {
return WindowManagerGlobal.ADD_DUPLICATE_ADD;
}
//关键点2 对于子窗口类型的处理 1、必须有父窗口 2，父窗口不能是子窗口类型
if (type >= FIRST_SUB_WINDOW && type <= LAST_SUB_WINDOW) {
parentWindow = windowForClientLocked(null, attrs.token, false);
if (parentWindow == null) {
return WindowManagerGlobal.ADD_BAD_SUBWINDOW_TOKEN;
}
if (parentWindow.mAttrs.type >= FIRST_SUB_WINDOW
&& parentWindow.mAttrs.type <= LAST_SUB_WINDOW) {
return WindowManagerGlobal.ADD_BAD_SUBWINDOW_TOKEN;
}}
...
boolean addToken = false;
//关键点3 根据IWindow 获取WindowToken WindowToken是窗口分组的基础，每个窗口必定有一个分组-
WindowToken token = mTokenMap.get(attrs.token);
//关键点4对于Toast类系统窗口，其attrs.token可以看做是null， 如果目前没有其他的类似系统窗口展示，token仍然获取不到，仍然要走新建流程
if (token == null) {
...
token = new WindowToken(this, attrs.token, -1, false);
addToken = true;
}
...
//关键点5 新建WindowState，WindowState与窗口是一对一的关系，可以看做是WMS中与窗口的抽象实体
WindowState win = new WindowState(this, session, client, token,
attachedWindow, appOp[0], seq, attrs, viewVisibility, displayContent);
...
if (addToken) {
mTokenMap.put(attrs.token, token);
}
win.attach();
mWindowMap.put(client.asBinder(), win);
...
//关键点6
addWindowToListInOrderLocked(win, true);
return res;
}
image.png
Activity的添加过程
activity的启动始于ActivityThread#handleLaunchActivity，其中反射创建了Activity对象并调用了Activity#attach方法。
final void attach(Context context, ActivityThread aThread,
Instrumentation instr, IBinder token, int ident,
Application application, Intent intent, ActivityInfo info,
CharSequence title, Activity parent, String id,
NonConfigurationInstances lastNonConfigurationInstances,
Configuration config, String referrer, IVoiceInteractor voiceInteractor) {
attachBaseContext(context);
//PhoneWindow是对DecorView的封装，内部包含Decorview
mWindow = new PhoneWindow(this);
//CallBack接口中定义了大量与用户操作有关的方法，这种方式下，就把用户的操作从Window中，传递给了Activity来处理。其中的一些常用的方法有dispathKeyEvent,dispathTouchEvent()等
mWindow.setCallback(this);
mWindow.setOnWindowDismissedCallback(this);
mWindow.getLayoutInflater().setPrivateFactory(this);
mWindow.setWindowManager((WindowManager)context.getSystemService(Context.WINDOW_SERVICE),
mToken, mComponent.flattenToString(),
(info.flags & ActivityInfo.FLAG_HARDWARE_ACCELERATED) != 0);
mWindowManager = mWindow.getWindowManager();
.........
}
接着回调到Activity#onCreate，其中一般会通过Activity#setContentView为Activity设置希望展示的界面。
public void setContentView(int layoutResID) {
// Note: FEATURE_CONTENT_TRANSITIONS may be set in the process of installing the window
// decor, when theme attributes and the like are crystalized. Do not check the feature
// before this happens.
if (mContentParent == null) {
installDecor();
} else if (!hasFeature(FEATURE_CONTENT_TRANSITIONS)) {
mContentParent.removeAllViews();
}
if (hasFeature(FEATURE_CONTENT_TRANSITIONS)) {
final Scene newScene = Scene.getSceneForLayout(mContentParent, layoutResID,
getContext());
transitionTo(newScene);
} else {
//为DecoraView添加子View
mLayoutInflater.inflate(layoutResID, mContentParent);
}
mContentParent.requestApplyInsets();
final Callback cb = getCallback();
if (cb != null && !isDestroyed()) {
cb.onContentChanged();
}
mContentParentExplicitlySet = true;
}
最后回调到ActivityThread#handleResumeActivity将decorview添加到WMS.
final void handleResumeActivity(IBinder token,
boolean clearHide, boolean isForward, boolean reallyResume) {
//调用activity.onResume，把activity数据记录更新到ActivityClientRecord
ActivityClientRecord r = performResumeActivity(token, clearHide);
if (r != null) {
final Activity a = r.activity;
//activity.mStartedActivity是用来标记启动Activity，有没有带返回值，一般我们startActivity(intent)是否默认是startActivityForResult(intent,-1)，默认值是-1，所以这里mStartedActivity = false
boolean willBeVisible = !a.mStartedActivity;
...
//mFinished标记Activity有没有结束，而r.window一开始activity并未赋值给ActivityClientRecord，所以这里为null
if (r.window == null && !a.mFinished && willBeVisible) {
r.window = r.activity.getWindow(); //赋值
View decor = r.window.getDecorView();
decor.setVisibility(View.INVISIBLE);
ViewManager wm = a.getWindowManager();
WindowManager.LayoutParams l = r.window.getAttributes();
a.mDecor = decor;
l.type = WindowManager.LayoutParams.TYPE_BASE_APPLICATION;
l.softInputMode |= forwardBit;
if (a.mVisibleFromClient) {
a.mWindowAdded = true;
//把当前的DecorView与WindowManager绑定一起
wm.addView(decor, l);
}
...
if (!r.activity.mFinished && willBeVisible
&& r.activity.mDecor != null && !r.hideForNow) {
//标记当前的Activity有没有设置新的配置参数，比如现在手机是横屏的，而之后你转成竖屏，那么这里的newCofig就会被赋值，表示参数改变
if (r.newConfig != null) {
r.tmpConfig.setTo(r.newConfig);
if (r.overrideConfig != null) {
r.tmpConfig.updateFrom(r.overrideConfig);
}
//然后调用这个方法回调，表示屏幕参数发生了改变
performConfigurationChanged(r.activity, r.tmpConfig);
...
WindowManager.LayoutParams l = r.window.getAttributes();
...//改变之后update更新当前窗口的DecorView
if (r.activity.mVisibleFromClient) {
ViewManager wm = a.getWindowManager();
View decor = r.window.getDecorView();
wm.updateViewLayout(decor, l);
}
}
//参数没改变
r.activity.mVisibleFromServer = true;
mNumVisibleActivities++;
if (r.activity.mVisibleFromClient) {
//由于前面设置了INVASIBLE，所以现在要把DecorView显示出来了
r.activity.makeVisible();
}
}
//通知ActivityManagerService，Activity完成Resumed
ActivityManagerNative.getDefault().activityResumed(token);
}
: