윈도우 매니저

public interface ViewManager{
    / / Add View
    public void addView(View view, ViewGroup.LayoutParams params);
    / / Update View
    public void updateViewLayout(View view, ViewGroup.LayoutParams params);
    / / Delete View
    public void removeView(View view);
}Copy code

public final class WindowManagerGlobal {
 
     public void addView(View view, ViewGroup.LayoutParams params,
                Display display, Window parentWindow) {
            / / Check the validity of the parameters
            ...
 
            //ViewRootImpl encapsulates the interaction between View and WindowManager
            ViewRootImpl root;
            View panelParentView = null;
 
            synchronized (mLock) {
                // Start watching for system property changes.
                if (mSystemPropertyUpdater == null) {
                    mSystemPropertyUpdater = new Runnable() {
                        @Override public void run() {
                            synchronized (mLock) {
                                for (int i = mRoots.size() - 1; i >= 0; --i) {
                                    mRoots.get(i).loadSystemProperties();
                                }
                            }
                        }
                    };
                    SystemProperties.addChangeCallback(mSystemPropertyUpdater);
                }
 
                int index = findViewLocked(view, false);
                if (index >= 0) {
                    if (mDyingViews.contains(view)) {
                        // Don't wait for MSG_DIE to make it's way through root's queue.
                        mRoots.get(index).doDie();
                    } else {
                        throw new IllegalStateException("View " + view
                                + " has already been added to the window manager.");
                    }
                    // The previous removeView() had not completed executing. Now it has.
                }
 
                // If this is a panel window, then find the window it is being
                // attached to for future reference.
                if (wparams.type >= WindowManager.LayoutParams.FIRST_SUB_WINDOW &&
                        wparams.type <= WindowManager.LayoutParams.LAST_SUB_WINDOW) {
                    final int count = mViews.size();
                    for (int i = 0; i < count; i++) {
                        if (mRoots.get(i).mWindow.asBinder() == wparams.token) {
                            panelParentView = mViews.get(i);
                        }
                    }
                }
 
                / / Build ViewRootImpl through the context
                root = new ViewRootImpl(view.getContext(), display);
 
                view.setLayoutParams(wparams);
 
                //mViews stores all View objects corresponding to Window
                mViews.add(view);
                //mRoots stores all ViewRootImpl objects corresponding to Window
                mRoots.add(root);
                //mParams stores all WindowManager.LayoutParams objects corresponding to Window
                mParams.add(wparams);
            }
 
            // do this last because it fires off messages to start doing things
            try {
                / / Call the ViewRootImpl.setView () method to complete the addition of Window and update the interface
                root.setView(view, wparams, panelParentView);
            } catch (RuntimeException e) {
                // BadTokenException or InvalidDisplayException, clean up.
                synchronized (mLock) {
                    final int index = findViewLocked(view, false);
                    if (index >= 0) {
                        removeViewLocked(index, true);
                    }
                }
                throw e;
            }
        }
 
}Copy code