Android Input输入系统之六：来电铃声时按键key的处理流程

女爷i 2023-06-30 08:47 39阅读 0赞

相关参考：  
[《Android按键Input KeyEvent》][Android_Input KeyEvent]  
[《Android Input输入系统之一：KeyEvent事件监听》][Android Input_KeyEvent]  
[《Android Input输入系统之二：KeyEvent注入事件及事件分发流程》][Android Input_KeyEvent 1]  
[《Android Input输入系统之三：KeyEvent事件分发和上层应用层对事件的接收》][Android Input_KeyEvent 2]  
[《Android Input输入系统之四：KeyEvent事件中的InputChannel通信》][Android Input_KeyEvent_InputChannel]  
[《Android Input输入系统之五：按键调节音量加减》][Android Input]

在《Android Input输入系统之二：KeyEvent注入事件及事件分发流程》中，讲述了事件向上分开的流程。

**注入事件的情况**：  
其中，InputDispatcher中注入按键消息，会进行分发，injectInputEvent()中会调用mPolicy->interceptKeyBeforeQueueing(&event, /*byref*/ policyFlags);

framework/native/services/inputflinger/InputDispatcher.cpp

int32_t InputDispatcher::injectInputEvent(const InputEvent* event, int32_t displayId,
            int32_t injectorPid, int32_t injectorUid, int32_t syncMode, int32_t timeoutMillis,
            uint32_t policyFlags) { 
    	//省略一部分代码
    	//...
    	
    	mPolicy->interceptKeyBeforeQueueing(&event, /*byref*/ policyFlags);
    	
    	//省略一部分代码
    	//...
    }

\\frameworks\\base\\services\\core\\java\\com\\android\\server\\policy\\PhoneWindowManager.java

public int interceptKeyBeforeQueueing(KeyEvent event, int policyFlags) { 
        //省略一部分代码
    	//...
    		// Handle special keys.
            switch (keyCode) { 
            	case KeyEvent.KEYCODE_VOLUME_DOWN:
                case KeyEvent.KEYCODE_VOLUME_UP:
                case KeyEvent.KEYCODE_VOLUME_MUTE:
    		        	if (down) { 
    		        		    TelecomManager telecomManager = getTelecommService();
    		                    if (telecomManager != null && !mHandleVolumeKeysInWM) { 
    		                        // When {@link #mHandleVolumeKeysInWM} is set, volume key events
    		                        // should be dispatched to WM.
    		                        if (telecomManager.isRinging()) { 
    		                            // If an incoming call is ringing, either VOLUME key means
    		                            // "silence ringer". We handle these keys here, rather than
    		                            // in the InCallScreen, to make sure we'll respond to them
    		                            // even if the InCallScreen hasn't come to the foreground yet.
    		                            // Look for the DOWN event here, to agree with the "fallback"
    		                            // behavior in the InCallScreen.
    		                            Log.i(TAG, "interceptKeyBeforeQueueing:"
    		                                  + " VOLUME key-down while ringing: Silence ringer!");
    		
    		                            // Silence the ringer. (It's safe to call this
    		                            // even if the ringer has already been silenced.)
    		                            // 静音来电铃声
    		                            telecomManager.silenceRinger();
    		                            MediaSessionLegacyHelper.getHelper(mContext).sendVolumeKeyEvent(
    		                                                                event, AudioManager.STREAM_RING, false);
    		
    		                            // And *don't* pass this key thru to the current activity
    		                            // (which is probably the InCallScreen.)
    		                            result &= ~ACTION_PASS_TO_USER;
    		                            break;
    		                        }
    		                    }
    		        	}
    		      case KeyEvent.KEYCODE_POWER:
    				        if (down) { 
    		                    interceptPowerKeyDown(event, interactive);
    		                    if((event.getFlags() & KeyEvent.FLAG_LONG_PRESS) == 0){ 
    		                        Intent intent = new Intent("com.hsae.keyevent.action");
    		                        intent.putExtra("event", event);
    		                        mContext.sendBroadcastAsUser(intent,UserHandle.ALL);
    		                    }
    		                } else { 
    		                    interceptPowerKeyUp(event, interactive, canceled);
    		                }
    		        	break;
            }
        //省略一部分代码
    	//...
    }
    
    private void interceptPowerKeyDown(KeyEvent event, boolean interactive) { 
    	//省略一部分代码
    	//...
    	    // Stop ringing or end call if configured to do so when power is pressed.
            TelecomManager telecomManager = getTelecommService();
            boolean hungUp = false;
            if (telecomManager != null) { 
                if (telecomManager.isRinging()) { 
                    // Pressing Power while there's a ringing incoming
                    // call should silence the ringer.men 
                    telecomManager.silenceRinger(); 
    				//Log.i(TAG,"interceptPowerKeyDown,telecomManager.silenceRinger()");
                } else if ((mIncallPowerBehavior
                        & Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR_HANGUP) != 0
                        && telecomManager.isInCall() && interactive) { 
                    // Otherwise, if "Power button ends call" is enabled,
                    // the Power button will hang up any current active call.
                    hungUp = telecomManager.endCall();
                }
            }
        //省略一部分代码
    	//...
    }

这两部分的逻辑都是在来电铃声时，调用了 telecomManager.silenceRinger(); 禁音了来电铃声。

[Android_Input KeyEvent]: https://blog.csdn.net/Sunxiaolin2016/article/details/103715355
[Android Input_KeyEvent]: https://blog.csdn.net/Sunxiaolin2016/article/details/103716912
[Android Input_KeyEvent 1]: https://blog.csdn.net/Sunxiaolin2016/article/details/103733280
[Android Input_KeyEvent 2]: https://blog.csdn.net/Sunxiaolin2016/article/details/103835884
[Android Input_KeyEvent_InputChannel]: https://blog.csdn.net/Sunxiaolin2016/article/details/103938729
[Android Input]: https://blog.csdn.net/Sunxiaolin2016/article/details/103958303