s60按鍵處理模型

做了一段時間航海桌面，被長按，短按，組合鍵各種按鍵邏輯搞的死去活來。

功能堆積的太多後，根本是一團漿糊。

 

正好開發到一個段落，重新整理了按鍵邏輯，把按鍵識別和執行功能分離。

 

識別模塊負責將按鍵事件串對應成可以接受的按鍵狀態。把不需要關心的噪音過濾掉。後面記作Filter

執行模塊根據按鍵狀態執行功能。

 

S60的按鍵事件分成3中類型：Down，Event，Up。

 

其中Event裏的Repeats屬性會變化，有0和1兩種值。還有一個Modify屬性，不過基本沒用。後面把Event且Repeat(0)記作Event，Event且Repeat(1)記作Repeat

 

一個短按過程

Down Event Up

一個長按過程

Down Event (Repeat)+ Up

 

常見情況是一個鍵的長按，短按有不同的功能。

必須先出現一個Event事件，然後等待後面的時間出現，如果是Up則是短按，如果是Repeat則是長按。如果是長按，需要忽略後面的Repeat和Up事件。

 

理想的實現是，通過Filter，在長按的時候收到一個狀態表示長按，短按的時候收到一個狀態表示短按。

由於狀態和之前收到是按鍵事件串是一一對應的，所以，狀態可以用一個堆棧表示，按照接受順序講按鍵事件入棧就可以了。

 

可以用一棵樹來描述按鍵接受邏輯。當做DFA來處理。

 

終結節點是可能的接受，在這個節點可以返回。

非終結節點是過度用的輸入事件。

 

一個識別短按的DFA看起來是這樣的

 

 

一個短按長按都要識別的DFA看起來是這樣的

 

 

定義下這個DFA。

每個節點包含以下屬性

 

1. 按鍵掃描碼

2. 按鍵字符碼

3. 重複標誌

4. 按鍵類型

5. 控制位（終結，匹配字符碼，匹配掃描碼，匹配重複標誌）

 

匹配時根據控制位進行對應判斷。控制位不表明的屬性不參與匹配。

 

然後把各種按鍵的DFA組合成一個DFA，作爲Filter的控制邏輯。

 

當一個鍵盤幾乎所有的鍵都有對應功能的時候，這個很管用

 

比如我現在做的這航海桌面。

每個按鍵的長按短按都有一種功能。

 

通過這個Filter，就可以簡單的把Event和Repeat組成的時間串，分解成互相沒關聯的事件。否還要記錄狀態，這十分麻煩。

 

下面 LS表示左鍵，RS表示右鍵，其他的都是字符按鍵。

 

這個看起來很漂亮。很多部分都一樣，都是長按短按都識別，創建代碼也會很簡單。只有一個左鍵（LS）比較特殊，因爲有短按長按識別還有組合鍵識別。

 

 

這裏有個組合鍵，LS再RS。

 

通過引入超時事件就很容易處理。每次收到UP事件後就引入一個超時。如果超時了，那麼這個匹配路徑就被強制退棧。如果這個路徑上有終結點，就返回最後一個終結點作爲最後結果。

 

其實這也就是一個普通了不能再普通的連續按鍵判斷邏輯用DFA畫一邊。

 

 

識別成功後怎麼知道到底是匹配了那個路徑？把記錄堆棧掃描一下就行了。

 

終於不用再爲這種東西煩惱了。

 

以後考慮加入用xml描述DFA，這樣就可以錄下操作，描述不同的行爲。

 

定義

 

/* * UiKeyFilter.h * * Created on: 2009-6-2 * Author: Slavik */ #ifndef UIKEYFILTER_H_ #define UIKEYFILTER_H_ #include <e32base.h> #include <W32STD.H> class IUiKeyFilterCallback { public: virtual ~IUiKeyFilterCallback() {} public: virtual void ProcessKeyEventL( const TKeyEvent& aKeyEvent, TEventCode aType ) =0; }; class CUiKeyFilter : public CTimer { public: enum TUiKeyFilterDFAFlag { ETerminator = 0x01, EUseKeyCode = 0x02, EUseScanCode = 0x04, EUseRepeats = 0x08 }; enum TPopEventReason { ENoReason, EMismatch, ETimeout }; class TUiKeyFilterDFA : public CBase { public: TInt iScanCode; TInt iKeyCode; TInt iRepeats; TEventCode iType; TUint iFlag; private: TUiKeyFilterDFA** iNext; TInt iNextCount; public: TUiKeyFilterDFA(); ~TUiKeyFilterDFA(); void AddSuccessorL( TUiKeyFilterDFA* ); TUiKeyFilterDFA* Successor(TInt aIndex); TInt SuccessorCount(); }; struct TUiKeyFilterStatus { TKeyEvent iKeyEvent; TEventCode iType; TUiKeyFilterDFA* iDFA; }; public: CUiKeyFilter( IUiKeyFilterCallback* aCallback ); ~CUiKeyFilter(); void ConstructL(); public: void FilterKeyEvent( const TKeyEvent& aKeyEvent, TEventCode aType ); void LoadDFAL(); void PopEventIfPossibleL( TPopEventReason aReason ); const TUiKeyFilterStatus* Top(); void Clear(); // get status from the top // aPrevIndex = 0, return top // aPrecIndex = 1, return top-1; // and so on const TUiKeyFilterStatus* Status( TInt aPrevIndex ); TInt CombineKeyInterval(); void SetCombineKeyInterval( TInt aMSec ); protected: void Pop(); void Push( const TKeyEvent& aKeyEvent, TEventCode& aType, TUiKeyFilterDFA* aDFA ); TUiKeyFilterDFA* DefaultUiKeyFilterDFAL(); TUiKeyFilterDFA* CreateEventAndRepeatDFA_ForScanCodeL( TInt aScanCode ); TUiKeyFilterDFA* CreateEventAndRepeatDFA_ForKeyCodeL( TInt aCode ); TUiKeyFilterDFA* CreateEventDFA_ForScanCodeL( TInt aScanCode ); TUiKeyFilterDFA* CreateEventDFA_ForKeyCodeL( TInt aCode ); TUiKeyFilterDFA* CreateScanCodeDFALC( TInt aScanCode, TEventCode aType, TBool aTerminator ); TUiKeyFilterDFA* CreateScanCodeDFALC( TInt aScanCode, TEventCode aType, TInt aRepeats, TBool aTerminator ); TUiKeyFilterDFA* CreateKeyCodeDFALC( TInt aCode, TEventCode aType, TBool aTerminator ); TUiKeyFilterDFA* CreateKeyCodeDFALC( TInt aCode, TEventCode aType, TInt aRepeats, TBool aTerminator ); TUiKeyFilterDFA* CreateDefaultKeyNoDFAL(); TUiKeyFilterDFA* CreateDefaultKeyYesDFAL(); TUiKeyFilterDFA* CreateDefaultKeyLeftDFAL(); TUiKeyFilterDFA* CreateDefaultKeyMidDFAL(); TUiKeyFilterDFA* CreateDefaultKeyRightDFAL(); protected: void RunL(); private: IUiKeyFilterCallback* iCallback; TUiKeyFilterDFA* iDFA; TUiKeyFilterStatus iStack[32]; TInt iStackSp; TInt iCombineKeyInterval; };

 

實現

 

#include "UiKeyFilter.h" #include "PhoneFeatureAfx.h" #include <COEAUI.H> CUiKeyFilter::TUiKeyFilterDFA::TUiKeyFilterDFA() : iScanCode(0), iKeyCode(0), iRepeats(0), iType(EEventKey), iFlag(0), iNext( NULL ), iNextCount(0) { } CUiKeyFilter::TUiKeyFilterDFA::~TUiKeyFilterDFA() { if( iNext ) { for( TInt i = 0; i < iNextCount; i++ ) { delete iNext[i]; } User::Free( iNext ); } } void CUiKeyFilter::TUiKeyFilterDFA::AddSuccessorL( CUiKeyFilter::TUiKeyFilterDFA* aNext ) { // new buf TInt count = iNextCount+1; TUiKeyFilterDFA** buf = (TUiKeyFilterDFA**)User::AllocZL( sizeof(TUiKeyFilterDFA*)*count ); if( iNextCount ) { // dump old data Mem::Copy( buf, iNext, sizeof(TUiKeyFilterDFA*)*iNextCount ); } buf[count-1] = aNext; if( iNext ) { // release old buf User::Free( iNext ); } iNext = buf; iNextCount = count; } CUiKeyFilter::TUiKeyFilterDFA* CUiKeyFilter::TUiKeyFilterDFA::Successor(TInt aIndex) { return iNext[aIndex]; } TInt CUiKeyFilter::TUiKeyFilterDFA::SuccessorCount() { return iNextCount; } CUiKeyFilter::CUiKeyFilter( IUiKeyFilterCallback* aCallback ) : CTimer( CActive::EPriorityUserInput ), iCallback( aCallback ), iStackSp(0), iCombineKeyInterval( 500000 ) { } CUiKeyFilter::~CUiKeyFilter() { if( iDFA ) { delete iDFA; } } void CUiKeyFilter::ConstructL() { CTimer::ConstructL(); CActiveScheduler::Add( this ); LoadDFAL(); } void CUiKeyFilter::FilterKeyEvent( const TKeyEvent& aKeyEvent, TEventCode aType ) { const TUiKeyFilterStatus* top = Top(); TUiKeyFilterDFA* dfa = iDFA; if( top ) { dfa = top->iDFA; } TBool match = EFalse; // scan the successor TInt count = dfa->SuccessorCount(); for( TInt i = 0; i < count; i++ ) { TUiKeyFilterDFA* n = dfa->Successor(i); if( aType != n->iType ) { // type not match continue; } if( EUseKeyCode & n->iFlag ) { // check key code if( aKeyEvent.iCode != n->iKeyCode ) { // the key code is not match continue; } } if( EUseScanCode & n->iFlag ) { // check scan code if( aKeyEvent.iScanCode != n->iScanCode ) { // the scan code is not match continue; } } if( EUseRepeats & n->iFlag ) { // check repeats if( aKeyEvent.iRepeats != n->iRepeats ) { // the repeats is not match continue; } } // found match match = ETrue; Push( aKeyEvent, aType, n ); // write the output if there is one if( 0 != (ETerminator & (n->iFlag)) && 0 == n->SuccessorCount() ) { PopEventIfPossibleL( ENoReason ); } break; } if( !match ) { PopEventIfPossibleL( EMismatch ); } if( EEventKeyUp == aType ) { if( IsActive() ) { Cancel(); } // active timeout After(iCombineKeyInterval); } } void CUiKeyFilter::PopEventIfPossibleL( TPopEventReason aReason ) { const TUiKeyFilterStatus* top = Top(); if( top ) { if( aReason || 0 == top->iDFA->SuccessorCount() ) { // the current input is not acceptable or the DFA is terminatored by a leaf // return the topest terminator in the stack // pop top Pop(); while( top && 0 == ( ETerminator & (top->iDFA->iFlag) ) ) { // check next top = Top(); Pop(); } if( top ) { // found one value // aKeyEvent = top->iKeyEvent; // aType = top->iType; iCallback->ProcessKeyEventL( top->iKeyEvent, top->iType ); } // clear the rest Clear(); } } } void CUiKeyFilter::RunL() { PopEventIfPossibleL( ETimeout ); } void CUiKeyFilter::LoadDFAL() { if( iDFA ) { delete iDFA; iDFA = NULL; } iDFA = DefaultUiKeyFilterDFAL(); } CUiKeyFilter::TUiKeyFilterDFA* CUiKeyFilter::CreateEventAndRepeatDFA_ForScanCodeL( TInt aScanCode ) { // start by a event key TUiKeyFilterDFA* s0 = CreateScanCodeDFALC( aScanCode, EEventKey, 0, ETrue ); // accept the repeat event TUiKeyFilterDFA* s1 = CreateScanCodeDFALC( aScanCode, EEventKey, 1, ETrue ); s0->AddSuccessorL( s1 ); CleanupStack::Pop(2,s0); return s0; } CUiKeyFilter::TUiKeyFilterDFA* CUiKeyFilter::CreateEventAndRepeatDFA_ForKeyCodeL( TInt aCode ) { // start by a event key TUiKeyFilterDFA* s0 = CreateKeyCodeDFALC( aCode, EEventKey, 0, ETrue ); // accept the repeat event TUiKeyFilterDFA* s1 = CreateKeyCodeDFALC( aCode, EEventKey, 1, ETrue ); s0->AddSuccessorL( s1 ); CleanupStack::Pop(2,s0); return s0; } CUiKeyFilter::TUiKeyFilterDFA* CUiKeyFilter::CreateEventDFA_ForScanCodeL( TInt aScanCode ) { TUiKeyFilterDFA* s0 = CreateScanCodeDFALC( aScanCode, EEventKey, ETrue ); CleanupStack::Pop( s0 ); return s0; } CUiKeyFilter::TUiKeyFilterDFA* CUiKeyFilter::CreateEventDFA_ForKeyCodeL( TInt aCode ) { TUiKeyFilterDFA* s0 = CreateKeyCodeDFALC( aCode, EEventKey, ETrue ); CleanupStack::Pop( s0 ); return s0; } CUiKeyFilter::TUiKeyFilterDFA* CUiKeyFilter::CreateDefaultKeyNoDFAL() { return CreateEventAndRepeatDFA_ForScanCodeL( EStdKeyNo ); // // accept the repeat event // TUiKeyFilterDFA* s0 = CreateScanCodeDFALC( EStdKeyNo, EEventKey, 0, EFalse ); // TUiKeyFilterDFA* s1 = CreateScanCodeDFALC( EStdKeyNo, EEventKeyUp, ETrue ); // s0->AddSuccessorL( s1 ); // CleanupStack::Pop(s1); // TUiKeyFilterDFA* s2 = CreateScanCodeDFALC( EStdKeyNo, EEventKey, 1, ETrue ); // s0->AddSuccessorL( s2 ); // CleanupStack::Pop(s2); // // CleanupStack::Pop(s0); // return s0; } CUiKeyFilter::TUiKeyFilterDFA* CUiKeyFilter::CreateDefaultKeyYesDFAL() { // start by a event key TUiKeyFilterDFA* s0 = CreateScanCodeDFALC( EStdKeyYes, EEventKey, ETrue ); CleanupStack::Pop( s0 ); return s0; } CUiKeyFilter::TUiKeyFilterDFA* CUiKeyFilter::CreateDefaultKeyLeftDFAL() { // return CreateEventAndRepeatDFA_ForScanCodeL( EStdKeyDevice0 ); // start by a event key TUiKeyFilterDFA* s00 = CreateScanCodeDFALC( EStdKeyDevice0, EEventKey, 0, ETrue ); // accept the repeat event TUiKeyFilterDFA* s11 = CreateScanCodeDFALC( EStdKeyDevice0, EEventKey, 1, ETrue ); s00->AddSuccessorL( s11 ); CleanupStack::Pop( s11 ); // accept the up event TUiKeyFilterDFA* s21 = CreateScanCodeDFALC( EStdKeyDevice0, EEventKeyUp, EFalse ); s00->AddSuccessorL( s21 ); CleanupStack::Pop( s21 ); // accept the right soft key down event TUiKeyFilterDFA* s22 = CreateScanCodeDFALC( EStdKeyDevice1, EEventKeyDown, EFalse ); s21->AddSuccessorL( s22 ); CleanupStack::Pop( s22 ); // accept the right soft key event TUiKeyFilterDFA* s23 = CreateScanCodeDFALC( EStdKeyDevice1, EEventKey, 0, EFalse ); s22->AddSuccessorL( s23 ); CleanupStack::Pop( s23 ); // accept the right soft key up TUiKeyFilterDFA* s24 = CreateScanCodeDFALC( EStdKeyDevice1, EEventKeyUp, ETrue ); s23->AddSuccessorL( s24 ); CleanupStack::Pop( s24 ); // completed CleanupStack::Pop( s00 ); return s00; } CUiKeyFilter::TUiKeyFilterDFA* CUiKeyFilter::CreateDefaultKeyMidDFAL() { TUiKeyFilterDFA* s0 = CreateScanCodeDFALC( EStdKeyDevice3, EEventKey, ETrue ); CleanupStack::Pop( s0 ); return s0; } CUiKeyFilter::TUiKeyFilterDFA* CUiKeyFilter::CreateDefaultKeyRightDFAL() { return CreateEventAndRepeatDFA_ForScanCodeL( EStdKeyDevice1 ); } CUiKeyFilter::TUiKeyFilterDFA* CUiKeyFilter::DefaultUiKeyFilterDFAL() { TBool hasQwertyKeyboard = SupportQwertyInputL(); // TInt count = 5 + 12 + ( hasQwertyKeyboard ? 26*2 : 0 ); // TUiKeyFilterDFA* dfa = (TUiKeyFilterDFA*)User::AllocZL( sizeof(TUiKeyFilterDFA) ); // dfa->iNext = (TUiKeyFilterDFA**)User::AllocZL( count*sizeof(TUiKeyFilterDFA*) ); // dfa->iNextCount = count; // // TUiKeyFilterDFA** w = dfa->iNext; TUiKeyFilterDFA* dfa = new (ELeave) TUiKeyFilterDFA; CleanupStack::PushL( dfa ); dfa->AddSuccessorL( CreateDefaultKeyNoDFAL() ); dfa->AddSuccessorL( CreateDefaultKeyNoDFAL() ); dfa->AddSuccessorL( CreateDefaultKeyYesDFAL() ); dfa->AddSuccessorL( CreateDefaultKeyLeftDFAL() ); dfa->AddSuccessorL( CreateDefaultKeyMidDFAL() ); dfa->AddSuccessorL( CreateDefaultKeyRightDFAL() ); // numbers TUint16 NUMS[] = { '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '*', '#', 0 }; TInt i =0; while( NUMS[i] ) { dfa->AddSuccessorL( CreateEventAndRepeatDFA_ForKeyCodeL( NUMS[i++] ) ); } // chars if( hasQwertyKeyboard ) { for( TUint c = 'a'; c <= 'z'; c++ ) { // dfa->AddSuccessorL( CreateEventDFA_ForKeyCodeL( c ) ); dfa->AddSuccessorL( CreateEventAndRepeatDFA_ForKeyCodeL( c ) ); } for( TUint c = 'A'; c <= 'Z'; c++ ) { // dfa->AddSuccessorL( CreateEventDFA_ForKeyCodeL( c ) ); dfa->AddSuccessorL( CreateEventAndRepeatDFA_ForKeyCodeL( c ) ); } } CleanupStack::Pop( dfa ); return dfa; } CUiKeyFilter::TUiKeyFilterDFA* CUiKeyFilter::CreateScanCodeDFALC( TInt aScanCode, TEventCode aType, TBool aTerminator ) { TUiKeyFilterDFA* dfa = new (ELeave) TUiKeyFilterDFA; CleanupStack::PushL( dfa ); dfa->iType = aType; dfa->iScanCode = aScanCode; dfa->iFlag = EUseScanCode | ( aTerminator ? ETerminator : 0 ); return dfa; } CUiKeyFilter::TUiKeyFilterDFA* CUiKeyFilter::CreateScanCodeDFALC( TInt aScanCode, TEventCode aType, TInt aRepeats, TBool aTerminator ) { TUiKeyFilterDFA* dfa = new (ELeave) TUiKeyFilterDFA; CleanupStack::PushL( dfa ); dfa->iType = aType; dfa->iScanCode = aScanCode; dfa->iRepeats = aRepeats; dfa->iFlag = EUseScanCode | EUseRepeats | ( aTerminator ? ETerminator : 0 ); return dfa; } CUiKeyFilter::TUiKeyFilterDFA* CUiKeyFilter::CreateKeyCodeDFALC( TInt aCode, TEventCode aType, TBool aTerminator ) { TUiKeyFilterDFA* dfa = new (ELeave) TUiKeyFilterDFA; CleanupStack::PushL( dfa ); dfa->iType = aType; dfa->iKeyCode = aCode; dfa->iFlag = EUseKeyCode | ( aTerminator ? ETerminator : 0 ); return dfa; } CUiKeyFilter::TUiKeyFilterDFA* CUiKeyFilter::CreateKeyCodeDFALC( TInt aCode, TEventCode aType, TInt aRepeats, TBool aTerminator ) { TUiKeyFilterDFA* dfa = new (ELeave) TUiKeyFilterDFA; CleanupStack::PushL( dfa ); dfa->iType = aType; dfa->iKeyCode = aCode; dfa->iRepeats = aRepeats; dfa->iFlag = EUseKeyCode | EUseRepeats | ( aTerminator ? ETerminator : 0 ); return dfa; } const CUiKeyFilter::TUiKeyFilterStatus* CUiKeyFilter::Top() { if( iStackSp ) { return iStack + (iStackSp-1); } return NULL; } // get status from the top // aPrevIndex = 0, return top // aPrecIndex = 1, return top-1; // and so on const CUiKeyFilter::TUiKeyFilterStatus* CUiKeyFilter::Status( TInt aPrevIndex ) { TInt offset = ( iStackSp-1-aPrevIndex ); if( offset < 0 || offset >= iStackSp ) { return NULL; } return iStack + offset; } void CUiKeyFilter::Push( const TKeyEvent& aKeyEvent, TEventCode& aType, TUiKeyFilterDFA* aDFA ) { iStack[iStackSp].iKeyEvent = aKeyEvent; iStack[iStackSp].iType = aType; iStack[iStackSp].iDFA = aDFA; iStackSp++; } void CUiKeyFilter::Pop() { iStackSp--; } void CUiKeyFilter::Clear() { iStackSp = 0; } TInt CUiKeyFilter::CombineKeyInterval() { return iCombineKeyInterval; } void CUiKeyFilter::SetCombineKeyInterval( TInt aMSec ) { iCombineKeyInterval = aMSec; }

 

使用Filter

 

TKeyResponse CHDesktopAppUi::HandleKeyEventL( const TKeyEvent& aKeyEvent,TEventCode aType) { // filter is not custructed yet if( NULL == iKeyFilter ) { return EKeyWasNotConsumed; } // send system event to filter TKeyEvent e = aKeyEvent; TEventCode t = aType; iKeyFilter->FilterKeyEvent( e, t ); return EKeyWasConsumed; } // receive event from filter void CHDesktopAppUi::ProcessKeyEventL( const TKeyEvent& aKeyEvent,TEventCode aType) { TBool repeat = ( aKeyEvent.iRepeats ? ETrue : EFalse ); switch( aKeyEvent.iScanCode ) { ... case EStdKeyYes: ShowLogsDialedCallL(); return; case EStdKeyNo: if( repeat ) { LOG("long press red key"); if( iUseRedKeyAsPowerKey ) { TurnOffPhone(); } else { if( !IsKeyboardLocked() ) { LockKeyboard(); } } } else { if( iTaskSwitcher ) { LOG("cycle task"); iTaskSwitcher->CycleTaskL( KSelf, iEikonEnv->RootWin().WindowGroupId() ); } } return; } switch( aKeyEvent.iCode ) { case '0': case 'm': case 'M': if( repeat ) { LaunchDefaultBrowserL(); return; } break; case '#': case 'j': case 'J': if( repeat ) { if( IsSilentL() ) { SwitchProfileL( 0 ); } else { SwitchProfileL( 1 ); } return; } break; } ... }