InCallScreen.java/updateScreen()分析

函數功能是在通話狀態改變時候，更新螢幕的

一、首先判定當前是否可以出現通話菜單

1，如果電話是空閑狀態，不可以出現菜單

2，如果有來電

    2.1  如果當前正在通話而且沒有等待的電話，可以彈出通話菜單

    2.2  否則，不能快顯功能表

二、如果是多方通話，更新會議面板

三、根據當前通話狀態，更新CallCard，就是螢幕中間顯示頭像那一塊。

四、是否顯示DTMF面板(通話過程中的那個撥號面板，如查話費時候，供你按人工提示輸入數位那個面板)

1，如果當前是響鈴狀態，不關閉撥號面板，但是清空裡面可能是上一個通話的數字

2，如果當前是豎屏模式，並且在通話狀態下，可以顯示撥號面板

五，更新等待接聽介面，如果有來電則轉到等待接聽介面（就是來電的時候那個介面）

六，更新menuButtonHint      在string.xml裡面有定義 <string name="menuButtonHint" msgid="4853215496220101699">"按 MENU 可以選擇通話選項。"</string>

 

 

部分代碼如下

 if (mInCallMenu != null) {                                                     
            // TODO: do this only if the menu is visible!                              
            if (VDBG) log("- updateScreen: updating menu items...");                   
            boolean okToShowMenu = mInCallMenu.updateItems(mPhone);                    
            if (!okToShowMenu) {                                                       
                // Uh oh: we were only trying to update the state of the               
                // menu items, but the logic in InCallMenu.updateItems()               
                // just decided the menu shouldn't be visible at all!                  
                // (That's probably means that the call ended                          
                // asynchronously while the menu was up.)                              
                //                                                                     
                // So take the menu down ASAP.                                         
                if (VDBG) log("- updateScreen: Tried to update menu; now need to dismiss!");
                // dismissMenu() has no effect if the menu is already closed.          
                dismissMenu(true);  // dismissImmediate = true
            }  
        }  
       
        if (mInCallScreenMode == InCallScreenMode.MANAGE_CONFERENCE) {                 
            if (VDBG) log("- updateScreen: manage conference mode (NOT updating in-call UI)...");
            updateManageConferencePanelIfNecessary();
            return;                                                                    
        } else if (mInCallScreenMode == InCallScreenMode.CALL_ENDED) {                 
            if (VDBG) log("- updateScreen: call ended state (NOT updating in-call UI)..."); 
            return;
        }  

        if (VDBG) log("- updateScreen: updating the in-call UI...");                   
        mCallCard.updateState(mPhone);                                                 
        updateDialpadVisibility();                                                     
        updateOnscreenAnswerUi();
        updateMenuButtonHint();