Launcher.java 文件源码

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {             
    if (isWorkspaceLocked())
        return true;

    boolean handled = super.onKeyDown(keyCode, event);
    if (!handled && acceptFilter() && keyCode != KeyEvent.KEYCODE_ENTER) {
        boolean gotKey = TextKeyListener.getInstance().onKeyDown(
                mWorkspace, mDefaultKeySsb, keyCode, event);
        if (gotKey && mDefaultKeySsb != null && mDefaultKeySsb.length() > 0) {
            // something usable has been typed - start a search
            // the typed text will be retrieved and cleared by
            // showSearchDialog()
            // If there are multiple keystrokes before the search dialog
            // takes focus,
            // onSearchRequested() will be called for every keystroke,
            // but it is idempotent, so it's fine.
            return onSearchRequested();
        }
    }

    // Eat the long press event so the keyboard doesn't come up.
    if (keyCode == KeyEvent.KEYCODE_MENU && event.isLongPress()) {
        return true;
    }

    if (keyCode == KeyEvent.KEYCODE_BACK && mThumbnailWorkspace.isVisible()) {
        int currPageIndex = ((CellLayout) mWorkspace.getChildAt(mWorkspace.getCurrentScreen())).getPageIndex();
           mThumbnailWorkspace.setmCurSelectedScreenIndex(currPageIndex);
        closeThumbnailWorkspace(true);
        return true;
    }
    return handled;
}