step1:调用ViewRootImpl的内部类ImeInputStage的成员函数onProcess来判断输入法是否处于激活状态

final class ImeInputStage extends AsyncInputStage
implements InputMethodManager.FinishedInputEventCallback {
public ImeInputStage(InputStage next, String traceCounter) {
super(next, traceCounter);
}
@Override
protected int onProcess(QueuedInputEvent q) {
if (mLastWasImTarget && !isInLocalFocusMode()) {
InputMethodManager imm = InputMethodManager.peekInstance();
if (imm != null) {
final InputEvent event = q.mEvent;
if (DEBUG_IMF) Log.v(TAG, "Sending input event to IME: " + event);
int result = imm.dispatchInputEvent(event, q, this, mHandler);
if (result == InputMethodManager.DISPATCH_HANDLED) {
return FINISH_HANDLED;
} else if (result == InputMethodManager.DISPATCH_NOT_HANDLED) {
return FINISH_NOT_HANDLED;
} else {return DEFER; // callback will be invoked later
}
}
}
return FORWARD;
} setp2:调用viewRootImpl的内部类ViewPostImeInputStage的成员函数processKeyEvent final class ViewPostImeInputStage extends InputStage {
    public ViewPostImeInputStage(InputStage next) {
super(next);
} @Override
protected int onProcess(QueuedInputEvent q) {
if (q.mEvent instanceof KeyEvent) {
return processKeyEvent(q);
} else {
// If delivering a new non-key event, make sure the window is
// now allowed to start updating.
handleDispatchDoneAnimating();
final int source = q.mEvent.getSource();
if ((source & InputDevice.SOURCE_CLASS_POINTER) != 0) {
return processPointerEvent(q);
} else if ((source & InputDevice.SOURCE_CLASS_TRACKBALL) != 0) {
return processTrackballEvent(q);
} else {
return processGenericMotionEvent(q);
}
}
} private int processKeyEvent(QueuedInputEvent q) {
final KeyEvent event = (KeyEvent) q.mEvent; if (event.getAction() != KeyEvent.ACTION_UP) {
// If delivering a new key event, make sure the window is
// now allowed to start updating.
handleDispatchDoneAnimating();
} // Deliver the key to the view hierarchy.
if (mView.dispatchKeyEvent(event)) {
return FINISH_HANDLED;
}
....
} setp3:在viewPostImenputStaged的processKeyEvent的函数中调用Decorview的成员函数dispatchKeyEvent
if (mView.dispatchKeyEvent(event)) {
            return FINISH_HANDLED;
}
step4:在DecorView的成员函数dispatchKeyEvent中调用Callback对象的dispatchKeyEvent函数
private final class DecorView extends FrameLayout implements RootViewSurfaceTaker {
...    
public DecorView(Context context, int featureId) {
super(context);
mFeatureId = featureId;
}
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
final int keyCode = event.getKeyCode();
final int action = event.getAction();
final boolean isDown = action == KeyEvent.ACTION_DOWN; if (isDown && (event.getRepeatCount() == 0)) {
// First handle chording of panel key: if a panel key is held
// but not released, try to execute a shortcut in it.
if ((mPanelChordingKey > 0) && (mPanelChordingKey != keyCode)) {
boolean handled = dispatchKeyShortcutEvent(event);
if (handled) {
return true;
}
}
if ((mPreparedPanel != null) && mPreparedPanel.isOpen) {
if (performPanelShortcut(mPreparedPanel, keyCode, event, 0)) {
return true;
}
}
}
if (!isDestroyed()) {
final Callback cb = getCallback();
final boolean handled = cb != null && mFeatureId < 0 ? cb.dispatchKeyEvent(event)
: super.dispatchKeyEvent(event);
if (handled) {
return true;
}
} return isDown ? PhoneWindow.this.onKeyDown(mFeatureId, event.getKeyCode(), event)
: PhoneWindow.this.onKeyUp(mFeatureId, event.getKeyCode(), event);
}
...
} setp5:
在Callback对象的dispatchKeyEvent的函数中调用PhoneWindow对象的superDispatchKeyEvent函数
public boolean dispatchKeyEvent(KeyEvent event) {
    onUserInteraction();

    // Let action bars open menus in response to the menu key prioritized over
// the window handling it
if (event.getKeyCode() == KeyEvent.KEYCODE_MENU &&
mActionBar != null && mActionBar.onMenuKeyEvent(event)) {
return true;
}
Window win = getWindow();
if (win.superDispatchKeyEvent(event)) {
return true;
}
View decor = mDecor;
if (decor == null) decor = win.getDecorView();
return event.dispatch(this, decor != null
? decor.getKeyDispatcherState() : null, this);
}
 
 


 

05-11 07:55