Android WindowManager窗口類型

WindowManager

WindowManager繼承自ViewManager，主要用來管理窗口的一些狀態、屬性、view增加、刪除、更新、窗口順序、消息收集和處理等。應用獲取方法：

Context.getSystemService(Context.WINDOW_SERVICE);

Window

表示頂級窗口，也就是主窗口，它有兩個實現類，PhoneWindow和MidWindow,一般的 activity對應的主要是PhoneWindow，在activity中經常使用的setContentView等方法就是在Window裡面實現。

從WindowManagerService角度看，一個窗口並不是Window類，而是一個View類。WindowManagerService收到用戶消息後，需要把消息派發到窗口，View類本身並不能直接接收WindowManagerService傳遞過來的消息，真正接收用戶消息的必須是IWindow類，而實現IWindow類的是ViewRoot.W類，每一個W內部都包含了一個View變量。
WmS並不介意該窗口（View）是屬於哪個應用程序的，WmS會按一定的規則判斷哪個窗口處於活動狀態，然後把用戶消息給W類，W類再把用戶消息傳遞給內部的View變量，剩下的消息處理就由View對象完成。
WindowManager的LayoutParams中窗口類型與定義：

frameworks\base\core\java\android\view\WindowManager.java

/**
 * Start of window types that represent normal application windows.
 *
 * ZMS:首個普通應用窗口
 */
public static final int FIRST_APPLICATION_WINDOW = 1;

/**
 * Window type: an application window that serves as the "base" window
 * of the overall application; all other application windows will
 * appear on top of it.
 * In multiuser systems shows only on the owning user's window.
 *
 * ZMS:基礎窗口-其他應用窗口會顯示在此窗口之上
 */
public static final int TYPE_BASE_APPLICATION   = 1;

/**
 * Window type: a normal application window.  The {@link #token} must be
 * an Activity token identifying who the window belongs to.
 * In multiuser systems shows only on the owning user's window.
 *
 * ZMS:普通應用窗口-此窗口需要歸屬於Activity，多用戶系統中僅僅在對應用戶的窗口中顯示
 */
public static final int TYPE_APPLICATION        = 2;

/**
 * Window type: special application window that is displayed while the
 * application is starting.  Not for use by applications themselves;
 * this is used by the system to display something until the
 * application can show its own windows.
 * In multiuser systems shows on all users' windows.
 *
 * ZMS:應用啟動窗口-應用啟動顯示的窗口，不受應用本身控制。由系統在應用顯示應用本身的窗口之前顯示。
 */
public static final int TYPE_APPLICATION_STARTING = 3;

/**
 * End of types of application windows.
 *
 * ZMS:終極應用窗口-所有Activity默認的窗口類型都是TYPE_APPLICATION，
 * WindowManagerService在進行窗口疊加時，會動態改變應用窗口的層值，但不會大於99。
 */
public static final int LAST_APPLICATION_WINDOW = 99;

/**
 * Start of types of sub-windows.  The {@link #token} of these windows
 * must be set to the window they are attached to.  These types of
 * windows are kept next to their attached window in Z-order, and their
 * coordinate space is relative to their attached window.
 *
 * ZMS:首個子窗口-依附於父窗口。子窗口在Z軸上鄰接父窗口，且協調空間與父窗口相關。
 * 子窗口是指該窗口必須要有一個父窗口，父窗口可以是一個應用類型窗口，也可以是任何其他類型的窗口。
 */
public static final int FIRST_SUB_WINDOW        = 1000;

/**
 * Window type: a panel on top of an application window.  These windows
 * appear on top of their attached window.
 *
 * ZMS:應用窗口子窗口-PopupWindow的默認類型
 */
public static final int TYPE_APPLICATION_PANEL  = FIRST_SUB_WINDOW;

/**
 * Window type: window for showing media (such as video).  These windows
 * are displayed behind their attached window.
 *
 * ZMS:用來顯示Media的窗口
 */
public static final int TYPE_APPLICATION_MEDIA  = FIRST_SUB_WINDOW+1;

/**
 * Window type: a sub-panel on top of an application window.  These
 * windows are displayed on top their attached window and any
 * {@link #TYPE_APPLICATION_PANEL} panels.
 *
 * ZMS:TYPE_APPLICATION_PANEL的子窗口
 */
public static final int TYPE_APPLICATION_SUB_PANEL = FIRST_SUB_WINDOW+2;

/** Window type: like {@link #TYPE_APPLICATION_PANEL}, but layout
 * of the window happens as that of a top-level window, not
 * as a child of its container.
 *
 * ZMS:OptionMenu、ContextMenu的默認類型
 */
public static final int TYPE_APPLICATION_ATTACHED_DIALOG = FIRST_SUB_WINDOW+3;

/**
 * Window type: window for showing overlays on top of media windows.
 * These windows are displayed between TYPE_APPLICATION_MEDIA and the
 * application window.  They should be translucent to be useful.  This
 * is a big ugly hack so:
 * @hide
 *
 * ZMS:TYPE_APPLICATION_MEDIA的重影窗口，顯示在TYPE_APPLICATION_MEDIA和應用窗口之間
 */
public static final int TYPE_APPLICATION_MEDIA_OVERLAY  = FIRST_SUB_WINDOW+4;

/**
 * End of types of sub-windows.
 *
 * ZMS:最後一個子窗口-創建子窗口時，客戶端可以指定窗口類型介於1000-1999之間，
 * 而WindowManagerService在進行窗口疊加時，會動態調整層值。
 */
public static final int LAST_SUB_WINDOW         = 1999;

/**
 * Start of system-specific window types.  These are not normally
 * created by applications.
 *
 * ZMS:首個系統窗口-系統窗口，系統窗口不需要對應任何Activity，也不需要有父窗口，
 * 對於應用程序而言，理論上是無法創建系統窗口的，因為所有的應用程序都沒有這個權限，
 * 然而系統進程卻可以創建系統窗口。
 */
public static final int FIRST_SYSTEM_WINDOW     = 2000;

/**
 * Window type: the status bar.  There can be only one status bar
 * window; it is placed at the top of the screen, and all other
 * windows are shifted down so they are below it.
 * In multiuser systems shows on all users' windows.
 *
 * ZMS:狀態欄窗口，層值2000。
 */
public static final int TYPE_STATUS_BAR         = FIRST_SYSTEM_WINDOW;

/**
 * Window type: the search bar.  There can be only one search bar
 * window; it is placed at the top of the screen.
 * In multiuser systems shows on all users' windows.
 *
 * ZMS:搜索條窗口，層值2001。
 */
public static final int TYPE_SEARCH_BAR         = FIRST_SYSTEM_WINDOW+1;

/**
 * Window type: phone.  These are non-application windows providing
 * user interaction with the phone (in particular incoming calls).
 * These windows are normally placed above all applications, but behind
 * the status bar.
 * In multiuser systems shows on all users' windows.
 *
 * ZMS:來電顯示窗口
 */
public static final int TYPE_PHONE              = FIRST_SYSTEM_WINDOW+2;

/**
 * Window type: system window, such as low power alert. These windows
 * are always on top of application windows.
 * In multiuser systems shows only on the owning user's window.
 *
 * ZMS:警告對話框
 */
public static final int TYPE_SYSTEM_ALERT       = FIRST_SYSTEM_WINDOW+3;

/**
 * Window type: keyguard window.
 * In multiuser systems shows on all users' windows.
 * @removed
 *
 * ZMS:鎖屏
 */
public static final int TYPE_KEYGUARD           = FIRST_SYSTEM_WINDOW+4;

/**
 * Window type: transient notifications.
 * In multiuser systems shows only on the owning user's window.
 *
 * ZMS:Toast窗口
 */
public static final int TYPE_TOAST              = FIRST_SYSTEM_WINDOW+5;

/**
 * Window type: system overlay windows, which need to be displayed
 * on top of everything else.  These windows must not take input
 * focus, or they will interfere with the keyguard.
 * In multiuser systems shows only on the owning user's window.
 *
 * ZMS:系統覆蓋窗口，顯示在所有窗口之上
 */
public static final int TYPE_SYSTEM_OVERLAY     = FIRST_SYSTEM_WINDOW+6;

/**
 * Window type: priority phone UI, which needs to be displayed even if
 * the keyguard is active.  These windows must not take input
 * focus, or they will interfere with the keyguard.
 * In multiuser systems shows on all users' windows.
 *
 * ZMS:在屏幕保護下的來電顯示窗口
 */
public static final int TYPE_PRIORITY_PHONE     = FIRST_SYSTEM_WINDOW+7;

/**
 * Window type: panel that slides out from the status bar
 * In multiuser systems shows on all users' windows.
 *
 * ZMS:滑動狀態欄後出現的窗口
 */
public static final int TYPE_SYSTEM_DIALOG      = FIRST_SYSTEM_WINDOW+8;

/**
 * Window type: dialogs that the keyguard shows
 * In multiuser systems shows on all users' windows.
 *
 * ZMS:鎖屏彈出的對話框
 */
public static final int TYPE_KEYGUARD_DIALOG    = FIRST_SYSTEM_WINDOW+9;

/**
 * Window type: internal system error windows, appear on top of
 * everything they can.
 * In multiuser systems shows only on the owning user's window.
 *
 * ZMS:系統錯誤窗口
 */
public static final int TYPE_SYSTEM_ERROR       = FIRST_SYSTEM_WINDOW+10;

/**
 * Window type: internal input methods windows, which appear above
 * the normal UI.  Application windows may be resized or panned to keep
 * the input focus visible while this window is displayed.
 * In multiuser systems shows only on the owning user's window.
 *
 * ZMS:輸入法窗口
 */
public static final int TYPE_INPUT_METHOD       = FIRST_SYSTEM_WINDOW+11;

/**
 * Window type: internal input methods dialog windows, which appear above
 * the current input method window.
 * In multiuser systems shows only on the owning user's window.
 * 
 * ZMS:輸入法中備選框對應的窗口
 */
public static final int TYPE_INPUT_METHOD_DIALOG= FIRST_SYSTEM_WINDOW+12;

/**
 * Window type: wallpaper window, placed behind any window that wants
 * to sit on top of the wallpaper.
 * In multiuser systems shows only on the owning user's window.
 *
 * ZMS:牆紙對應的窗口
 */
public static final int TYPE_WALLPAPER          = FIRST_SYSTEM_WINDOW+13;

/**
 * Window type: panel that slides out from over the status bar
 * In multiuser systems shows on all users' windows.
 *
 * ZMS:滑動狀態欄後出現的面板窗口
 */
public static final int TYPE_STATUS_BAR_PANEL   = FIRST_SYSTEM_WINDOW+14;

/**
 * Window type: secure system overlay windows, which need to be displayed
 * on top of everything else.  These windows must not take input
 * focus, or they will interfere with the keyguard.
 *
 * This is exactly like {@link #TYPE_SYSTEM_OVERLAY} except that only the
 * system itself is allowed to create these overlays.  Applications cannot
 * obtain permission to create secure system overlays.
 *
 * In multiuser systems shows only on the owning user's window.
 * @hide
 * 
 * ZMS:安全系統覆蓋窗口，顯示在所有窗口之上。
 */
public static final int TYPE_SECURE_SYSTEM_OVERLAY = FIRST_SYSTEM_WINDOW+15;

/**
 * Window type: the drag-and-drop pseudowindow.  There is only one
 * drag layer (at most), and it is placed on top of all other windows.
 * In multiuser systems shows only on the owning user's window.
 * @hide
 *
 * ZMS:拖動放開窗口。
 */
public static final int TYPE_DRAG               = FIRST_SYSTEM_WINDOW+16;

/**
 * Window type: panel that slides out from under the status bar
 * In multiuser systems shows on all users' windows.
 * @hide
 *
 * ZMS:滑動狀態欄顯示的面板窗口。
 */
public static final int TYPE_STATUS_BAR_SUB_PANEL = FIRST_SYSTEM_WINDOW+17;

/**
 * Window type: (mouse) pointer
 * In multiuser systems shows on all users' windows.
 * @hide
 *
 * ZMS:鼠標窗口。
 */
public static final int TYPE_POINTER = FIRST_SYSTEM_WINDOW+18;

/**
 * Window type: Navigation bar (when distinct from status bar)
 * In multiuser systems shows on all users' windows.
 * @hide
 *
 * ZMS:導航欄窗口
 */
public static final int TYPE_NAVIGATION_BAR = FIRST_SYSTEM_WINDOW+19;

/**
 * Window type: The volume level overlay/dialog shown when the user
 * changes the system volume.
 * In multiuser systems shows on all users' windows.
 * @hide
 *
 * ZMS:音量調節窗口
 */
public static final int TYPE_VOLUME_OVERLAY = FIRST_SYSTEM_WINDOW+20;

/**
 * Window type: The boot progress dialog, goes on top of everything
 * in the world.
 * In multiuser systems shows on all users' windows.
 * @hide
 *
 * ZMS:系統啟動進程對話框窗口-在其他內容之上。
 */
public static final int TYPE_BOOT_PROGRESS = FIRST_SYSTEM_WINDOW+21;

/**
 * Window type: Fake window to consume touch events when the navigation
 * bar is hidden.
 * In multiuser systems shows on all users' windows.
 * @hide
 *
 * ZMS:隱藏導航欄時消化觸摸事件窗口-當導航欄隱藏時，用來處理消費觸摸事件的模擬窗口。
 */
public static final int TYPE_HIDDEN_NAV_CONSUMER = FIRST_SYSTEM_WINDOW+22;

/**
 * Window type: Dreams (screen saver) window, just above keyguard.
 * In multiuser systems shows only on the owning user's window.
 * @hide
 *
 * ZMS:LDreams屏保窗口，僅在鎖屏窗口之上。
 */
public static final int TYPE_DREAM = FIRST_SYSTEM_WINDOW+23;

/**
 * Window type: Navigation bar panel (when navigation bar is distinct from status bar)
 * In multiuser systems shows on all users' windows.
 * @hide
 *
 * ZMS:導航欄面板窗口
 */
public static final int TYPE_NAVIGATION_BAR_PANEL = FIRST_SYSTEM_WINDOW+24;

/**
 * Window type: Behind the universe of the real windows.
 * In multiuser systems shows on all users' windows.
 * @hide
 *
 * ZMS:全局背景窗口
 */
public static final int TYPE_UNIVERSE_BACKGROUND = FIRST_SYSTEM_WINDOW+25;

/**
 * Window type: Display overlay window.  Used to simulate secondary display devices.
 * In multiuser systems shows on all users' windows.
 * @hide
 *
 * ZMS:顯示重繪窗口，用來模擬第二屏顯示設備。
 */
public static final int TYPE_DISPLAY_OVERLAY = FIRST_SYSTEM_WINDOW+26;

/**
 * Window type: Magnification overlay window. Used to highlight the magnified
 * portion of a display when accessibility magnification is enabled.
 * In multiuser systems shows on all users' windows.
 * @hide
 *
 * ZMS:放大Overlay窗口-當輔助功能放大開啟時，用來放大高亮顯示。
 */
public static final int TYPE_MAGNIFICATION_OVERLAY = FIRST_SYSTEM_WINDOW+27;

/**
 * Window type: keyguard scrim window. Shows if keyguard needs to be restarted.
 * In multiuser systems shows on all users' windows.
 * @hide
 *
 * ZMS:鎖屏遮罩窗口，在鎖屏需要重啟時顯示。
 */
public static final int TYPE_KEYGUARD_SCRIM           = FIRST_SYSTEM_WINDOW+29;

/**
 * Window type: Window for Presentation on top of private
 * virtual display.
 *
 * ZMS:安全信息窗口。
 */
public static final int TYPE_PRIVATE_PRESENTATION = FIRST_SYSTEM_WINDOW+30;

/**
 * Window type: Windows in the voice interaction layer.
 * @hide
 *
 * ZMS:語音交互窗口。
 */
public static final int TYPE_VOICE_INTERACTION = FIRST_SYSTEM_WINDOW+31;

/**
 * Window type: Windows that are overlaid only by an {@link
 * android.accessibilityservice.AccessibilityService} for interception of
 * user interactions without changing the windows an accessibility service
 * can introspect. In particular, an accessibility service can introspect
 * only windows that a sighted user can interact with which is they can touch
 * these windows or can type into these windows. For example, if there
 * is a full screen accessibility overlay that is touchable, the windows
 * below it will be introspectable by an accessibility service regardless
 * they are covered by a touchable window.
 *
 * ZMS:輔助功能窗口。
 */
public static final int TYPE_ACCESSIBILITY_OVERLAY = FIRST_SYSTEM_WINDOW+32;

/**
 * M:
 * Window type: Top most
 * @hide
 *
 * ZMS:TopMost窗口。
 */
public static final int TYPE_TOP_MOST = FIRST_SYSTEM_WINDOW + 33;

/**
 * End of types of system windows.
 *
 * ZMS:終極系統窗口。
 */
public static final int LAST_SYSTEM_WINDOW      = 2999;