Android system service-windowmanager

Windowmanager is an important service in Android ). The windowmanager service is globally unique. It translates user operations into commands and sends them to various windows displayed on the interface. Activity registers top-level controls to window manager,
When you touch the screen or keyboard, the window manager will notify you, and when the control has some requests, it will also be sent back to the window manager through viewparent. To complete the entire communication process.
The window mechanism of the entire android system is based on a windowmanager interface. You can add a View to the screen or delete the view from the screen. It targets the screen at one end of the object, and the view at the other end. It creates a view through the addview method of windowmanager.
Windowmanager. layoutparams has different properties, and the effect is different. For example, you can create a system top-level window to implement the floating window effect! The windowmanager method is very simple. Basically, three addview, removeview, and updateviewlayout are used. Interface, while windowmanager. layoutparams has many attributes, which are very rich. For details, refer to the following description.

 

How to obtain the windowmanager instance? Here is a small example to illustrate the following:

Button BB = new button (getapplicationcontext (); <br/> windowmanager wmmanager = (windowmanager) getsystemservice (context. window_service); <br/> windowmanager. layoutparams wmparams = new windowmanager. layoutparams (); <br/>/** <br/> * The following are windowmanager. layoutparams-related attributes <br/> * for specific purposes, see the SDK documentation <br/> */<br/> wmparams. type = 2002; // here is the key. You can also try 2003 <br/> wmparams. format = 1; <br/>/** <br/> * the flags here are also critical <br/> * the code is actually wmparams. flags | = flag_not_focusable; <br/> * 40 is the default attribute of wmparams (32) + flag_not_focusable (8) <br/> */<br/> wmparams. flags = 40; <br/> wmparams. width = 40; <br/> wmparams. height = 40; </P> <p> wmmanager. addview (BB, wmparams); // create a view

The above is a simple example. A button object is created, And the buttonview is added through the addview of the windowmanager Instance Object and displayed according to the corresponding layoutparams parameters.

 

Some interfaces of the windowmanager object are described as follows:

1) Abstract display getdefadisplay display (); // obtain the Display object displayed by default.
2) Abstract void removeviewimmediate (view); // a special extension of removeview (view). The view. ondetachedfromwindow () method at the view level can be called immediately before the method is returned.

 

The following describes the nested internal class layoutparams of the windowmanager interface.

Windowmanager. layoutparams is a nested class of the windowmanager interface. It inherits from viewgroup. layoutparams. Its content is rich. In fact, the main content of windowmanager. Java is defined by this class. Next we will analyze this class:

 

Definition

Public static class windowmanager. layoutparams
Extends viewgroup. layoutparams implements parcelable

Inheritance relationship

Java. Lang. Object
Using Android. View. viewgroup. layoutparams
Using Android. View. windowmanager. layoutparams

Inherited attributes and constants

Attributes inherited from ViewManager. layoutparams:
Android: layout_height
Specifies the Basic height of the view.

Android: layout_width
Specifies the basic width of the view.

Constants inherited from ViewManager. layoutparams:
Fill_parent
Wrap_content
Match_parent

 

Two variables:

Width
Height

 

Attribute and available constant Definitions

1. Public int X;
If the gravity attribute is ignored, it indicates the absolute X position of the window.
What is the gravity attribute? Simply put, it is how the window is docked.
After gravity. Left or gravity. Right is set, the X value indicates the distance to a specific edge.
 
2. Public int y;
If the gravity attribute is ignored, it indicates the absolute y position of the window.
After gravity. Top or gravity. Bottom is set, the Y value indicates the distance to a specific edge.
 
3. Public float horizontalweight;
Public float verticalweight;
In the vertical or horizontal direction, how much extra space (pixels) is reserved for the associated view ). If it is 0, the view cannot be stretched.
In other cases, the Extended Space (pixels) is evenly distributed by widgets.

4. Public int type;
Window Type. There are three main types:
A) applicationwindows:
The value is between first_application_window and last_application_window.
Is a common, top-layer application window. You must set the token of the activity.
B) sub_windows:
The value is between first_sub_window and last_sub_window.
Associated with the top-level window, the token must be set as the token of the host window to which it is attached.
C) systemwindows:
The value is between first_system_window and last_system_window.
Used for specific system functions. It cannot be used in applications and requires special permissions.

The value of type is defined below:

Application Window.
Public static final int first_application_window = 1;

The "base" Window of all program windows, and other application windows are displayed on it.
Public static final int type_base_application = 1;

Common functions and procedures. The token must be set as the activity token to indicate who the window belongs.
Public static final int type_application = 2;

The window displayed when the application starts. The application itself does not use this type.
It is used for the system to display some information until the application can open its own window.
Public static final int type_application_starting = 3;

The application window ends.
Public static final int last_application_window = 99;

Subwindow. The Z-order and coordinate spaces of subwindows depend on their host windows.
Public static final int first_sub_window = 1000;

The panel window is displayed on the upper layer of the host window.
Public static final int type_application_panel = first_sub_window;

Media window, such as video. Displayed at the lower layer of the host window.
Public static final int type_application_media = first_sub_window + 1;

The Child Panel of the application window. Displayed on the upper layer of all panel windows. (The more "sub", the closer the GUI is)
Public static final int type_application_sub_panel = first_sub_window + 2;

Dialog box. Similar to a panel window, draw a window similar to a top-level window, rather than a child window of the host.
Public static final int type_application_attached_dialog = first_sub_window + 3;

Media information. The display must be transparent (translucent) between the media layer and the program window. (For example, show subtitles)
Public static final int type_application_media_overlay = first_sub_window + 4;

The child window ends. (End of types of sub-Windows)
Public static final int last_sub_window = 1999;

System window. Non-application creation.
Public static final int first_system_window = 2000;

Status Bar. There can be only one status bar; it is located at the top of the screen, and other windows are located below it.
Public static final int type_status_bar = first_system_window;

Search bar. There can be only one search bar; it is located above the screen.
Public static final int type_search_bar = first_system_window + 1;

Phone window. It is used for telephone interaction (especially incoming calls ). It is placed above all applications and under the status bar.
Public static final int type_phone = first_system_window + 2;

System prompt. It always appears in the application window.
Public static final int type_system_alert = first_system_window + 3;

Screen lock window.
Public static final int type_keyguard = first_system_window + 4;

Information Window. Display toast.
Public static final int type_toast = first_system_window + 5;

System top-level window. It is displayed on top of everything else. This window cannot obtain the input focus; otherwise, the screen lock will be affected.
Public static final int type_system_overlay = first_system_window + 6;

The phone number is preferred. It is displayed when the screen is locked. This window cannot obtain the input focus; otherwise, the screen lock will be affected.
Public static final int type_priority_phone = first_system_window + 7;

System dialog box. (For example, the volume adjustment box ).
Public static final int type_system_dialog = first_system_window + 8;

The dialog box displayed when the screen is locked.
Public static final int type_keyguard_dialog = first_system_window + 9;

The system internal error message is displayed on top of all content.
Public static final int type_system_error = first_system_window + 10;

The internal input method window is displayed on the normal UI. Applications can be laid out again to avoid being overwritten by this window.
Public static final int type_input_method = first_system_window + 11;

The internal input method dialog box is displayed on top of the current input method window.
Public static final int type_input_method_dialog = first_system_window + 12;

Wallpaper window.
Public static final int type_wallpaper = first_system_window + 13;

Slide Panel of the status bar.
Public static final int type_status_bar_panel = first_system_window + 14;

The system window ends.
Public static final int last_system_window = 2999;

5. Public int memorytype;
Specifies the memory buffer type used by the window. The default value is normal.

The value of memorytype is defined below:
The window buffer is in the primary memory.
Public static final int memory_type_normal = 0;

The window buffer is located in the memory area that can be accessed by DMA or hardware acceleration.
Public static final int memory_type_hardware = 1;

The window buffer is located in the area that can be accessed by the graphic accelerator.
Public static final int memory_type_gpu = 2;

The window buffer does not have its own buffer and cannot be locked. The buffer is provided by the local method.
Public static final int memory_type_push_buffers = 3;

6. Public int flags;
Behavior option/flag. The default value is none.

The value of flags is defined below:
The content after the window is dimmed.
Public static final int flag_dim_behind = 0x00000002;

The content after the window is blurred.
Public static final int flag_blur_behind = 0x00000004;

Do not get focus.
Public static final int flag_not_focusable = 0x00000008;

Do not accept touch screen events.
Public static final int flag_not_touchable = 0x00000010;

When the window can get the focus (the flag_not_focusalbe option is not set), the point device event (mouse, touch screen) outside the window is still sent to the subsequent window for processing. Otherwise, it excludes all vertex device events, regardless of whether they occur within the window.
Public static final int flag_not_touch_modal = 0x00000020;

If this flag is set, when the device sleep, click the touch screen and the device will receive this first touch event.
Usually, the first touch event is consumed by the system, and the user will not see the response of their clicking on the screen.
Public static final int flag_touchable_when_waking = 0x00000040;

When this window is visible to the user, keep the device open and keep the brightness unchanged.
Public static final int flag_keep_screen_on = 0x00000080;

The window occupies the entire screen, ignoring the surrounding decorative border (such as the status bar ). This window should take into account the content of the decorative border.
Public static final int flag_layout_in_screen = 0x00000100;

The window can be extended out of the screen.
Public static final int flag_layout_no_limits = 0x00000200;

Hide all screen decorations (such as status bars) when the window is displayed ). Make the window occupy the entire display area.
Public static final int flag_fullscreen = 0x00000400;

This option overwrites the flag_fullscreen option and forces the screen Decoration (such as status bar) to pop up.
Public static final int flag_force_not_fullscreen = 0x00000800;

Jitter. Display Method of translucent. It is also called "Point-through ". Devices with poor image processing often use dot-passthrough instead of Alpha mixing.
Public static final int flag_dither = 0x00001000;

Screen is not allowed.
Public static final int flag_secure = 0x00002000;

The layout parameter is used to indicate the display ratio.
Public static final int flag_scaled = 0x00004000;

This option prevents cheek misoperation on the screen when the screen may have a face.
Public static final int flag_ignore_cheek_presses = 0x00008000;

When the request is laid out, your window may appear above or below the status bar, thus blocking. When this option is set, the window manager ensures that the window content is not covered by the decoration bar (status bar.
Public static final int flag_layout_inset_decor = 0x00010000;

Reverse the flag_not_focusable option.
If both the flag_not_focusable option and the current option are set, the window can interact with the input method and allow the input method window to overwrite;
If this option is not set for flag_not_focusable, the window cannot interact with the input method, and the input method window can be overwritten.
Public static final int flag_alt_focusable_im = 0x00020000;

If you have set flag_not_touch_modal, when a touch screen event occurs outside the window, you can receive a motionevent. action_outside event by setting this flag. Note that you will not receive the complete down/move/Up event. You can only receive action_outside when you first go down the event.
Public static final int flag_watch_outside_touch = 0x00040000;

When the screen lock is set, the window is displayed. This gives the application window priority over the screen lock interface. You can use the flag_keep_screen_on option to light up the screen and display it directly before the screen lock. You can use the flag_dismiss_keyguard option to directly unlock the unlocked screen. This option is only used for the top-level full screen window.
Public static final int flag_show_when_locked = 0x00080000;

The request system wallpaper is displayed behind your window. The window must be translucent.
Public static final int flag_show_wallpaper = 0x00100000;

Once the window is displayed, the system will light up the screen, just as the user wakes up the device.
Public static final int flag_turn_screen_on = 0x00200000;

Unlock the screen. Only the screen lock interface is not encrypted can be unlocked. If the screen lock is encrypted, you can see the screen only after unlocking it, unless the flag_show_when_locked option is set.
Public static final int flag_dismiss_keyguard = 0x00400000;

When the screen lock interface fades out, it continues to run its animation.
Public static final int flag_keep_surface_while_animating = 0x10000000;

Display the window in the original size. It is used to run programs in compatible mode.
Public static final int flag_compatible_window = 0x20000000;

Used in the system dialog box. The window for setting this option will obtain the focus unconditionally.
Public static final int flag_system_error = 0x40000000;

7. Public int softinputmode;
Soft input mode options:

The following options are related to softinputmode:
Whether the soft input area is visible.
Public static final int soft_input_mask_state = 0x0f;

The status is not specified.
Public static final int soft_input_state_unspecified = 0;

Do not modify the status of the soft input area.
Public static final int soft_input_state_unchanged = 1;

Hide the Input Method Area (when the user enters the window ).
Public static final int soft_input_state_hidden = 2;

When the window gets focus, the input method area is hidden.
Public static final int soft_input_state_always_hidden = 3;

Display the Input Method Area (when the user enters the window ).
Public static final int soft_input_state_visible = 4;

When the window gets focus, the input method area is displayed.
Public static final int soft_input_state_always_visible = 5;

The window should be adjusted to adapt to the soft input window.
Public static final int soft_input_mask_adjust = 0xf0;

If the status is not specified, the system will try to select an input method style based on the window content.
Public static final int soft_input_adjust_unspecified = 0x00;

When the input method is displayed, the window size can be re-calculated so that the content is not overwritten by the input method.
It cannot be used together with soft_input_adjusp_pan. If neither of them is set, the system automatically sets an option based on the window content.
Public static final int soft_input_adjust_resize = 0x10;

Translation window when the input method is displayed. It does not need to handle size changes. The frame can move the window to ensure that the input focus is visible.
It cannot be used together with soft_input_adjust_resize. If neither of them is set, the system automatically sets an option based on the window content.
Public static final int soft_input_adjust_pan = 0x20;

When you go to this window, it is automatically set by the system, so do not set it.
This flag is automatically cleared when the window is displayed.
Public static final int soft_input_is_forward_navigation = 0x100;

8. Public int gravity;
Gravity attribute. What is the gravity attribute? Simply put, it is how the window is docked.

9. Public float horizontalmargin;
Horizontal margin, the distance between the container and the widget, percentage of the container width.

10. Public float verticalmargin;
Vertical margin.

11. Public int format;
The expected bitmap format. The default value is opacity. See Android. Graphics. pixelformat.

12. Public int windowanimations;
Animation settings used in the window. It must be a system resource rather than an application resource because the window manager cannot access the application.

13. Public float alpha = 1.0f;
The translucent value of the entire window. The value 1.0 indicates opacity, and the value 0.0 indicates full transparency.

14. Public float dimamount = 1.0f;
It takes effect after flag_dim_behind is set. This variable indicates the degree to which the subsequent window is dimmed. 1.0 indicates that the image is completely opaque, and 0.0 indicates that the image is not dimmed.

15. Public float screenbrightness =-1.0f;
It is used to overwrite the screen brightness set by the user. The screen brightness set by the Application User. The brightness changes from 0 to 1.

 

16. Public ibinder token = NULL;
The identifier of the window. (Identifier for this window. This will be usually be filled in for you .)

17. Public String packagename = NULL;
The package name of the window.

18. Public int screenorientation = activityinfo. screen_orientation_unspecified;
For more information about the screen direction, see Android. content. PM. activityinfo # screenorientation.

19. The internal buffer used by the backup/recovery parameters in compatibility mode.
Public int [] mcompatibilityparamsbackup = NULL;

 

Common Methods

1. Public final int copyfrom (windowmanager. layoutparams O );
Various "change" information is defined below, which is used by the copyfrom function.
Public staticfinal int layout_changed = 1 <0;
Public staticfinal int type_changed = 1 <1;
Public staticfinal int flags_changed = 1 <2;
Public staticfinal int format_changed = 1 <3;
Public staticfinal int animation_changed = 1 <4;
Public staticfinal int dim_amount_changed = 1 <5;
Public staticfinal int title_changed = 1 <6;
Public staticfinal int alpha_changed = 1 <7;
Public staticfinal int memory_type_changed = 1 <8;
Public staticfinal int soft_input_mode_changed = 1 <9;
Public staticfinal int screen_orientation_changed = 1 <10;
Public staticfinal int screen_brightness_changed = 1 <11;