richmemo: win32 + holding selection direction for GetXXX operations (that are strictly selection based).

reduce the number of redundant OnChange events, only call them on real event happening.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@5117 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/richmemo/win32/win32richmemo.pas

@@ -250,9 +250,25 @@ begin
   Result:=false; // we need to catch just notifications,
     // any other message should be handled in a "Default" manner
     // So, default result is false;
-  hdr:=PNMHDR(LParam);
   case Msg of
+    WM_COMMAND: begin
+      case HIWORD(WParam) of
+        EN_UPDATE: begin
+          // https://msdn.microsoft.com/en-us/library/windows/desktop/bb761687(v=vs.85).aspx
+          // EN_UPDATE is just a notification, that the edit is to be redrawn
+          Result:=true;
+        end;
+        EN_CHANGE: begin
+          // https://msdn.microsoft.com/en-us/library/windows/desktop/hh768384(v=vs.85).aspx
+          // Despite of what documentation claims (WM_NOTIFY), EN_CHANGE is notified by WM_COMMAND
+          if Assigned(AWinControl) and (AWinControl is TCustomRichMemo) then
+            TIntCustomRichMemo(AWinControl).Change;
+          Result:=true;
+        end;
+      end;
+    end;
     WM_NOTIFY: begin
+      hdr:=PNMHDR(LParam);
       case hdr^.code of
         EN_SELCHANGE:
           begin
@@ -539,7 +555,7 @@ begin
   FinishCreateWindow(AWinControl, Params, false);
 
   eventmask := SendMessage(AWinControl.Handle, EM_GETEVENTMASK, 0, 0);
-  eventmask := eventmask or ENM_SELCHANGE or ENM_LINK;
+  eventmask := eventmask or ENM_SELCHANGE or ENM_LINK or ENM_CHANGE;
   SendMessage(AWinControl.Handle, EM_SETEVENTMASK, 0, eventmask);
 
   // Limitless text. However, the value would be overwritten by a consequent
@@ -581,8 +597,7 @@ end;
 class function TWin32WSCustomRichMemo.GetTextAttributes(const AWinControl: TWinControl; 
   TextStart: Integer; var Params: TIntFontParams): Boolean;  
 var
-  OrigStart : Integer;
+  Orig      : TCHARRANGE;
-  OrigLen   : Integer;
   eventmask : LongWord;
 begin
   if not Assigned(RichEditManager) or not Assigned(AWinControl) then begin
@@ -592,12 +607,14 @@ begin
   InitFontParams(Params);
   eventmask := RichEditManager.SetEventMask(AWinControl.Handle, 0);
 
-  RichEditManager.GetSelection(AWinControl.Handle, OrigStart, OrigLen);
-
   LockRedraw(TCustomRichMemo(AWinControl), AWinControl.Handle);
+
+  RichEditManager.GetSelRange(AWinControl.Handle, Orig);
+
   RichEditManager.SetSelection(AWinControl.Handle, TextStart, 1);
   Result := RichEditManager.GetSelectedTextStyle(AWinControl.Handle, Params );
-  RichEditManager.SetSelection(AWinControl.Handle, OrigStart, OrigLen);
+
+  RichEditManager.SetSelRange(AWinControl.Handle, Orig);
   UnlockRedraw(TCustomRichMemo(AWinControl), AWinControl.Handle, false);
 
   RichEditManager.SetEventMask(AWinControl.Handle,eventmask);
@@ -669,8 +686,7 @@ class function TWin32WSCustomRichMemo.GetStyleRange(
   const AWinControl: TWinControl; TextStart: Integer; var RangeStart, 
   RangeLen: Integer): Boolean;  
 var
-  OrigStart : Integer;
+  Orig      : TCharRange;
-  OrigLen   : Integer;
   eventmask : longword;
 begin
   if not Assigned(RichEditManager) or not Assigned(AWinControl) then begin
@@ -679,17 +695,17 @@ begin
   end;
 
   eventmask := RichEditManager.SetEventMask(AWinControl.Handle, 0);
-
-  RichEditManager.GetSelection(AWinControl.Handle, OrigStart, OrigLen);
   LockRedraw(TCustomRichMemo(AWinControl), AWinControl.Handle);
 
+  RichEditManager.GetSelRange(AWinControl.Handle, Orig);
+
   RichEditManager.SetSelection(AWinControl.Handle, TextStart, 1);
   try
     Result := RichEditManager.GetStyleRange(AWinControl.Handle, TextStart, RangeStart, RangeLen);
   except
   end;
   
-  RichEditManager.SetSelection(AWinControl.Handle, OrigStart, OrigLen);
+  RichEditManager.SetSelRange(AWinControl.Handle, Orig);
   UnlockRedraw(TCustomRichMemo(AWinControl), AWinControl.Handle, false);
   
   RichEditManager.SetEventMask(AWinControl.Handle, eventmask);
@@ -724,8 +740,7 @@ end;
 class function TWin32WSCustomRichMemo.GetTextUIParams(const AWinControl: TWinControl; TextStart: Integer;
   var ui: TTextUIParam): Boolean;
 var
-  OrigStart : Integer;
+  Orig      : TCHARRANGE;
-  OrigLen   : Integer;
   eventmask : Integer;
 begin
   if not Assigned(RichEditManager) or not Assigned(AWinControl) then begin
@@ -734,12 +749,14 @@ begin
   end;
 
   eventmask := RichEditManager.SetEventMask(AWinControl.Handle, 0);
-  RichEditManager.GetSelection(AWinControl.Handle, OrigStart, OrigLen);
-
   LockRedraw( TCustomRichMemo(AWinControl), AWinControl.Handle);
+
+  RichEditManager.GetSelRange(AWinControl.Handle, Orig);
+
   RichEditManager.SetSelection(AWinControl.Handle, TextStart, 1);
   RichEditManager.GetTextUIStyle(AWinControl.Handle, ui);
-  RichEditManager.SetSelection(AWinControl.Handle, OrigStart, OrigLen);
+
+  RichEditManager.SetSelRange(AWinControl.Handle, Orig);
   UnlockRedraw( TCustomRichMemo(AWinControl), AWinControl.Handle);
 
   RichEditManager.SetEventMask(AWinControl.Handle, eventmask);
@@ -774,6 +791,8 @@ begin
 
   eventmask:=RichEditManager.SetEventMask(AWinControl.Handle, 0);
 
+  LockRedraw( TCustomRichMemo(AWinControl), AWinControl.Handle);
+
   RichEditManager.GetPara2(AWinControl.Handle, TextStart, para);
   case para.wAlignment of
     PFA_CENTER:  AAlign:=paCenter;
@@ -782,6 +801,7 @@ begin
   else
     AAlign:=paLeft;
   end;
+  UnlockRedraw( TCustomRichMemo(AWinControl), AWinControl.Handle );
   RichEditManager.SetEventMask(AWinControl.Handle, eventmask);
 
   Result:=true;
@@ -1063,6 +1083,7 @@ class function TWin32WSCustomRichMemo.GetSubText(
   var utxt: UnicodeString): Boolean;
 var
   eventmask : Integer;
+  Orig      : TCharRange;
   OrigStart : Integer;
   OrigLen   : Integer;
   NeedLock  : Boolean;
@@ -1078,7 +1099,7 @@ begin
   NeedLock := (OrigStart <> TextStart) or (OrigLen <> TextLen);
   if NeedLock then begin
     LockRedraw( TCustomRichMemo(AWinControl), Hnd);
-    RichEditManager.SetSelection(Hnd, TextStart, TextLen);
+    RichEditManager.GetSelRange(Hnd, Orig);
   end;
 
   isUnicode:=AsUnicode;
@@ -1089,7 +1110,7 @@ begin
   end;
 
   if NeedLock then begin
-    RichEditManager.SetSelection(Hnd, OrigStart, OrigLen);
+    RichEditManager.SetSelRange(Hnd, Orig);
     UnlockRedraw( TCustomRichMemo(AWinControl), Hnd);
   end;
   RichEditManager.SetEventMask(Hnd, eventmask);

components/richmemo/win32/win32richmemoproc.pas

@@ -173,6 +173,11 @@ type
     class function GetStyleRange(RichEditWnd: Handle; TextStart: Integer; var RangeStart, RangeLen: Integer): Boolean; virtual;
     class procedure GetSelection(RichEditWnd: Handle; var TextStart, TextLen: Integer); virtual;      
     class procedure SetSelection(RichEditWnd: Handle; TextStart, TextLen: Integer); virtual;
+
+    // WARNING: GetSelRange, is causing changes in Selection!
+    class procedure GetSelRange(RichEditWnd: Handle; var sr: TCHARRANGE); virtual;
+    class procedure SetSelRange(RichEditWnd: Handle; const sr: TCHARRANGE); virtual;
+
     class procedure SetHideSelection(RichEditWnd: Handle; AValue: Boolean); virtual;
     class function LoadRichText(RichEditWnd: Handle; ASrc: TStream): Boolean; virtual;
     class function SaveRichText(RichEditWnd: Handle; ADst: TStream): Boolean; virtual;
@@ -647,6 +652,38 @@ begin
   SendMessage(RichEditWnd, EM_EXSETSEL, 0, PtrInt(@Range));
 end;
 
+class procedure TRichEditManager.GetSelRange(RichEditWnd: Handle; var sr: TCHARRANGE);
+var
+  st: Integer;
+begin
+  sr.cpMax := 0;
+  sr.cpMin := 0;
+  st:=0;
+  SendMessage(RichEditWnd, EM_EXGETSEL, 0, PtrInt(@sr));
+  // EM_EXGETSEL - always returns min and max, in the math order
+  // (where math is lower, than max)
+  // This, however, doesn't match the seletion direction.
+  // Selection direction is done by either mouse (right to left) and (left to right)
+  // or by holding SHIFT key and moving left to right.
+  // EM_EXSETSEL - repsects the specified sr.cpMax and sr.cpMin order
+
+  // Resetting the selection.
+  // This is a bit hacky, BUT the selection would be reset
+  // towards the direction of the selection
+  SendMessage(RichEditWnd, EM_SETSEL, -1, 0);
+  SendMessage(RichEditWnd, EM_GETSEL, WPARAM(@st), 0);
+
+  if st=sr.cpMin then begin // right-to-left selection
+    sr.cpMin:=sr.cpMax;
+    sr.cpMax:=st;
+  end;
+end;
+
+class procedure TRichEditManager.SetSelRange(RichEditWnd: Handle; const sr: TCHARRANGE);
+begin
+  SendMessage(RichEditWnd, EM_EXSETSEL, 0, PtrInt(@sr));
+end;
+
 class procedure TRichEditManager.SetHideSelection(RichEditWnd: Handle; AValue: Boolean);
 var
   style  : LResult;
@@ -720,9 +757,9 @@ class procedure TRichEditManager.SetText(RichEditWnd:Handle;
 var
   AnsiText : AnsiString;
   txt      : PChar;
-  s, l     : Integer;
+  sr       : TCHARRANGE;
 begin
-  GetSelection(RichEditWnd, s, l);
+  GetSelRange(RichEditWnd, sr);
   SetSelection(RichEditWnd, TextStart, ReplaceLength);
 
   txt:=nil;
@@ -735,7 +772,7 @@ begin
     SendMessageA(RichEditWnd, EM_REPLACESEL, 0, LPARAM(txt));
   end;
 
-  SetSelection(RichEditWnd, s, l);
+  SetSelRange(RichEditWnd, sr);
 end;
 
 class function TRichEditManager.GetTextW(RichEditWnd: Handle;
@@ -801,9 +838,9 @@ end;
 class procedure TRichEditManager.GetPara2(RichEditWnd: Handle; TextStart: Integer;
   var para: PARAFORMAT2);
 var
-  s, l     : Integer;
+  sr : TCHARRANGE;
 begin
-  GetSelection(RichEditWnd, s, l);
+  GetSelRange(RichEditWnd, sr);
 
   SetSelection(RichEditWnd, TextStart, 0);
 
@@ -811,18 +848,20 @@ begin
   para.cbSize:=sizeof(para);
   SendMessagea(RichEditWnd, EM_GETPARAFORMAT, 0, LPARAM(@para));
 
-  SetSelection(RichEditWnd, s, l);
+  SetSelRange(RichEditWnd, sr);
 end;
 
 class procedure TRichEditManager.SetPara2(RichEditWnd: Handle;
   TextStart, TextLen: Integer; const para: PARAFORMAT2);
 var
-  s, l     : Integer;
+  sr : TCHARRANGE;
 begin
-  GetSelection(RichEditWnd, s, l);
+  GetSelRange(RichEditWnd, sr);
+
   SetSelection(RichEditWnd, TextStart, TextLen);
   SendMessagea(RichEditWnd, EM_SETPARAFORMAT, 0, LPARAM(@para));
-  SetSelection(RichEditWnd, s, l);
+
+  SetSelRange(RichEditWnd, sr);
 end;
 
 class function TRichEditManager.Find(RichEditWnd: THandle; const ANiddle: WideString; const ASearch: TIntSearchOpt): Integer; overload;