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      1 /*
      2  * Copyright (C) 2006 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package android.view;
     18 
     19 import android.annotation.NonNull;
     20 import android.os.IBinder;
     21 
     22 /**
     23  * Provides low-level communication with the system window manager for
     24  * operations that are bound to a particular context, display or parent window.
     25  * Instances of this object are sensitive to the compatibility info associated
     26  * with the running application.
     27  *
     28  * This object implements the {@link ViewManager} interface,
     29  * allowing you to add any View subclass as a top-level window on the screen.
     30  * Additional window manager specific layout parameters are defined for
     31  * control over how windows are displayed.  It also implements the {@link WindowManager}
     32  * interface, allowing you to control the displays attached to the device.
     33  *
     34  * <p>Applications will not normally use WindowManager directly, instead relying
     35  * on the higher-level facilities in {@link android.app.Activity} and
     36  * {@link android.app.Dialog}.
     37  *
     38  * <p>Even for low-level window manager access, it is almost never correct to use
     39  * this class.  For example, {@link android.app.Activity#getWindowManager}
     40  * provides a window manager for adding windows that are associated with that
     41  * activity -- the window manager will not normally allow you to add arbitrary
     42  * windows that are not associated with an activity.
     43  *
     44  * @see WindowManager
     45  * @see WindowManagerGlobal
     46  * @hide
     47  */
     48 public final class WindowManagerImpl implements WindowManager {
     49     private final WindowManagerGlobal mGlobal = WindowManagerGlobal.getInstance();
     50     private final Display mDisplay;
     51     private final Window mParentWindow;
     52 
     53     private IBinder mDefaultToken;
     54 
     55     public WindowManagerImpl(Display display) {
     56         this(display, null);
     57     }
     58 
     59     private WindowManagerImpl(Display display, Window parentWindow) {
     60         mDisplay = display;
     61         mParentWindow = parentWindow;
     62     }
     63 
     64     public WindowManagerImpl createLocalWindowManager(Window parentWindow) {
     65         return new WindowManagerImpl(mDisplay, parentWindow);
     66     }
     67 
     68     public WindowManagerImpl createPresentationWindowManager(Display display) {
     69         return new WindowManagerImpl(display, mParentWindow);
     70     }
     71 
     72     /**
     73      * Sets the window token to assign when none is specified by the client or
     74      * available from the parent window.
     75      *
     76      * @param token The default token to assign.
     77      */
     78     public void setDefaultToken(IBinder token) {
     79         mDefaultToken = token;
     80     }
     81 
     82     @Override
     83     public void addView(@NonNull View view, @NonNull ViewGroup.LayoutParams params) {
     84         applyDefaultToken(params);
     85         mGlobal.addView(view, params, mDisplay, mParentWindow);
     86     }
     87 
     88     @Override
     89     public void updateViewLayout(@NonNull View view, @NonNull ViewGroup.LayoutParams params) {
     90         applyDefaultToken(params);
     91         mGlobal.updateViewLayout(view, params);
     92     }
     93 
     94     private void applyDefaultToken(@NonNull ViewGroup.LayoutParams params) {
     95         // Only use the default token if we don't have a parent window.
     96         if (mDefaultToken != null && mParentWindow == null) {
     97             if (!(params instanceof WindowManager.LayoutParams)) {
     98                 throw new IllegalArgumentException("Params must be WindowManager.LayoutParams");
     99             }
    100 
    101             // Only use the default token if we don't already have a token.
    102             final WindowManager.LayoutParams wparams = (WindowManager.LayoutParams) params;
    103             if (wparams.token == null) {
    104                 wparams.token = mDefaultToken;
    105             }
    106         }
    107     }
    108 
    109     @Override
    110     public void removeView(View view) {
    111         mGlobal.removeView(view, false);
    112     }
    113 
    114     @Override
    115     public void removeViewImmediate(View view) {
    116         mGlobal.removeView(view, true);
    117     }
    118 
    119     @Override
    120     public Display getDefaultDisplay() {
    121         return mDisplay;
    122     }
    123 }
    124