Android 虚拟按键 触感 调用流程

PhoneWindowManager.java

1. public int interceptKeyBeforeQueueing(KeyEvent event, int policyFlags, boolean isScreenOn) {
2.  
3. if (down && (policyFlags & WindowManagerPolicy.FLAG_VIRTUAL) != 0
4. && event.getRepeatCount() == 0) {
5. performHapticFeedbackLw(null, HapticFeedbackConstants.VIRTUAL_KEY, false);
6. }

1. public boolean performHapticFeedbackLw(WindowState win, int effectId, boolean always) {
2. Log.e("++++++++++++++++++++++", "++++++++++performHapticFeedbackLw PhoneWindowManager.java");
3. final boolean hapticsDisabled = Settings.System.getInt(mContext.getContentResolver(),
4. Settings.System.HAPTIC_FEEDBACK_ENABLED, 0) == 0;
5. if (!always && (hapticsDisabled || mKeyguardMediator.isShowingAndNotHidden())) {
6. return false;
7. }
8. long[] pattern = null;
9. switch (effectId) {
10. case HapticFeedbackConstants.LONG_PRESS:
11. pattern = mLongPressVibePattern;
12. break;
13. case HapticFeedbackConstants.VIRTUAL_KEY:
14. pattern = mVirtualKeyVibePattern;
15. break;
16. case HapticFeedbackConstants.KEYBOARD_TAP:
17. pattern = mKeyboardTapVibePattern;
18. break;
19. case HapticFeedbackConstants.SAFE_MODE_DISABLED:
20. pattern = mSafeModeDisabledVibePattern;
21. break;
22. case HapticFeedbackConstants.SAFE_MODE_ENABLED:
23. pattern = mSafeModeEnabledVibePattern;
24. break;
25. default:
26. return false;
27. }
28. if (pattern.length == 1) {
29. // One-shot vibration
30. mVibrator.vibrate(pattern[0]);
31. } else {
32. // Pattern vibration
33. mVibrator.vibrate(pattern, -1);
34. }
35. return true;
36. }

其实还有其他的地方会用到振动，但是他们有自己的performHapticFeedback函数。比如：

View.java （这个会在长按桌面，图标时振动）

1. public boolean performHapticFeedback(int feedbackConstant, int flags) {
2. if (mAttachInfo == null) {
3. return false;
4. }
5. //noinspection SimplifiableIfStatement
6. if ((flags & HapticFeedbackConstants.FLAG_IGNORE_VIEW_SETTING) == 0
7. && !isHapticFeedbackEnabled()) {
8. return false;
9. }
10. return mAttachInfo.mRootCallbacks.performHapticFeedback(feedbackConstant,
11. (flags & HapticFeedbackConstants.FLAG_IGNORE_GLOBAL_SETTING) != 0);
12. }

Android4.0上的虚拟的键也是通过他调用的振动。可以看KeyButtonView.java，他就是继承的View。
好像这个是通过Session.java调用了PhoneWindowManager.java的performHapticFeedbackLw()。