richmemo: added GetParaRange methods and its win32 implementation

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@3783 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/richmemo/richmemo.pas

@@ -63,6 +63,14 @@ type
   TSearchOption = (soMatchCase, soWholeWord, soBackward);
   TSearchOptions = set of TSearchOption;
 
+  TParaRange = record
+    start      : Integer; // the first character in the paragraph
+    lenghtNoBr : Integer; // the length of the paragraph, excluding the line break character
+    length     : Integer; // the length of the paragrpah, including the line break, if present
+    // the last line in the control doesn't contain a line break character,
+    // thus length = lengthNoBr
+  end;
+
 
 type
   TRichMemoObject = class(TObject);
@@ -97,6 +105,8 @@ type
     procedure SetParaMetric(TextStart, TextLen: Integer; const AMetric: TParaMetric); virtual;
     function GetParaNumbering(TextStart: Integer; var ANumber: TParaNumbering): Boolean; virtual;
     procedure SetParaNumbering(TextStart, TextLen: Integer; const ANumber: TParaNumbering); virtual;
+    function GetParaRange(CharOfs: Integer; var ParaRange: TParaRange): Boolean; virtual;
+    function GetParaRange(CharOfs: Integer; var TextStart, TextLength: Integer): Boolean;
 
     procedure SetTextAttributes(TextStart, TextLen: Integer; AFont: TFont);
     procedure SetRangeColor(TextStart, TextLength: Integer; FontColor: TColor);
@@ -350,6 +360,25 @@ begin
     TWSCustomRichMemoClass(WidgetSetClass).SetParaNumbering(Self, TextStart, TextLen, ANumber);
 end;
 
+function TCustomRichMemo.GetParaRange(CharOfs: Integer;
+  var ParaRange: TParaRange): Boolean;
+begin
+  Result:=false;
+  if not HandleAllocated then HandleNeeded;
+  if HandleAllocated then
+    Result:=TWSCustomRichMemoClass(WidgetSetClass).GetParaRange(Self, CharOfs, ParaRange);
+end;
+
+function TCustomRichMemo.GetParaRange(CharOfs: Integer; var TextStart,
+  TextLength: Integer): Boolean;
+var
+  p : TParaRange;
+begin
+  Result:=GetParaRange(CharOfs, p);
+  TextStart:=p.start;
+  TextLength:=p.length;
+end;
+
 function TCustomRichMemo.GetContStyleLength(TextStart: Integer): Integer;
 var
   ofs, len  : Integer;

components/richmemo/win32/win32richmemo.pas

@@ -91,6 +91,8 @@ type
       var AMetrics: TIntParaMetric): Boolean; override;
     class procedure SetParaMetric(const AWinControl: TWinControl; TextStart, TextLength: Integer;
       const AMetrics: TIntParaMetric); override;
+    class function GetParaRange(const AWinControl: TWinControl; TextStart: Integer;
+      var ParaRange: TParaRange): Boolean; override;
 
     class function GetParaNumbering(const AWinControl: TWinControl; TextStart: Integer;
       var ANumber: TIntParaNumbering): Boolean; override;
@@ -519,6 +521,17 @@ begin
   RichEditManager.SetPara2(AWinControl.Handle, TextStart, TextLength, para);
 end;
 
+class function TWin32WSCustomRichMemo.GetParaRange(const AWinControl: TWinControl;
+  TextStart: Integer; var ParaRange: TParaRange): Boolean;
+begin
+  if not Assigned(AWinControl) then
+    Result:=False
+  else begin
+    RichEditManager.GetParaRange(AWinControl.Handle, TextStart, ParaRange);
+    Result:=true;
+  end;
+end;
+
 const
   PFN_ARABIC   = 2;
   PFN_LCLETTER = 3;

components/richmemo/win32/win32richmemoproc.pas

@@ -148,6 +148,7 @@ type
 
   TRichEditManager = class(TObject)
   public
+    class function GetTextLength(RichEditWnd: Handle): Integer;
     class function SetSelectedTextStyle(RichEditWnd: Handle; Params: TIntFontParams): Boolean; virtual;
     class function GetSelectedTextStyle(RichEditWnd: Handle; var Params: TIntFontParams): Boolean; virtual;
     class function GetStyleRange(RichEditWnd: Handle; TextStart: Integer; var RangeStart, RangeLen: Integer): Boolean; virtual; 
@@ -160,6 +161,7 @@ type
     class procedure GetPara2(RichEditWnd: Handle; TextStart: Integer; var para: PARAFORMAT2); virtual;
     class procedure SetPara2(RichEditWnd: Handle; TextStart, TextLen: Integer; const para: PARAFORMAT2); virtual;
     class function Find(RichEditWnd: THandle; const ANiddle: WideString; const ASearch: TIntSearchOpt): Integer; virtual;
+    class procedure GetParaRange(RichEditWnd: Handle; TextStart: integer; var para: TParaRange); virtual;
   end;
   TRichManagerClass = class of TRichEditManager;
                      
@@ -172,6 +174,10 @@ procedure CopyStringToCharArray(const s: String; var Chrs: array of Char; ChrsSi
 function FontStylesToEffects(Styles: TFontStyles): LongWord;
 function EffectsToFontStyles(Effects: LongWord): TFontStyles;
 
+const
+  CP_UNICODE = 1200;
+  HardBreak  = #13;
+
 implementation
 
 const
@@ -240,6 +246,16 @@ end;
 
 { TRichEditManager }
 
+class function TRichEditManager.GetTextLength(RichEditWnd: Handle): Integer;
+var
+  textlen : TGETTEXTEX;
+begin
+  FillChar(textlen, sizeof(textlen), 0);
+  textlen.flags := GTL_NUMCHARS or GTL_PRECISE;
+  textlen.codepage := CP_UNICODE;
+  Result := SendMessage(RichEditWnd, EM_GETTEXTLENGTHEX, WPARAM(@textlen), 0);
+end;
+
 class function TRichEditManager.SetSelectedTextStyle(RichEditWnd: Handle; 
   Params: TIntFontParams): Boolean;
 var
@@ -314,7 +330,6 @@ var
   last    : Integer;
   
 const
-  CP_UNICODE = 1200;  
   ALL_MASK = CFM_BOLD or CFM_ITALIC or CFM_STRIKEOUT or CFM_UNDERLINE or 
              CFM_SIZE or CFM_COLOR or CFM_FACE;
 begin
@@ -322,7 +337,7 @@ begin
   if (RichEditWnd = 0) then Exit;
   
   FillChar(textlen, sizeof(textlen), 0);
-  textlen.flags := GTL_NUMCHARS or GTL_USECRLF or GTL_PRECISE;
+  textlen.flags := GTL_NUMCHARS or GTL_PRECISE;
   textlen.codepage := CP_UNICODE;
   len := SendMessage(RichEditWnd, EM_GETTEXTLENGTHEX, WPARAM(@textlen), 0);
   Result := TextStart < len;
@@ -584,6 +599,58 @@ begin
   end;
 end;
 
+class procedure TRichEditManager.GetParaRange(RichEditWnd: Handle; TextStart: integer;
+  var para: TParaRange);
+var
+  line: Integer;
+  txtlen: Integer;
+  st: Integer;
+  ln: Integer;
+  toend: Integer;
+  tost: Integer;
+  buf : string[16];
+  rng : TTEXTRANGEA;
+  res : Integer;
+begin
+  txtlen:=GetTextLength(RichEditWnd);
+  // lines are NOT paragraphs, but wordwrapped lines
+  line:=SendMessage(RichEditWnd, EM_EXLINEFROMCHAR, 0, TextStart);
+  st:=SendMessage(RichEditWnd, EM_LINEINDEX, line, 0);
+  tost:=st;
+  toend:=0;
+
+  while tost>0 do begin
+    rng.lpstrText:=@buf[1];
+    rng.chrg.cpMin:=tost-1;
+    rng.chrg.cpMax:=tost;
+    buf[1]:=#0;
+    res:=SendMessageA(RichEditWnd, EM_GETTEXTRANGE, 0, LPARAM(@rng));
+    if (buf[1]=HardBreak) then
+      Break // found the beggining of the paragraph
+    else begin
+      line:=SendMessage(RichEditWnd, EM_EXLINEFROMCHAR, 0, tost-2); // getting the line before the linebreak
+      tost:=SendMessage(RichEditWnd, EM_LINEINDEX, line, 0);
+      inc(toend, SendMessage(RichEditWnd, EM_LINELENGTH, line, 0));
+    end;
+  end;
+
+  repeat
+    ln:=SendMessage(RichEditWnd, EM_LINELENGTH, st, 0);
+    inc(toend, ln);
+    inc(st, ln);
+    rng.lpstrText:=@buf[1];
+    rng.chrg.cpMin:=st;
+    rng.chrg.cpMax:=st+1;
+    buf[1]:=#0;
+    res:=SendMessage(RichEditWnd, EM_GETTEXTRANGE, 0, LPARAM(@rng));
+  until (res=0) or (buf[1] = HardBreak);
+
+  para.start:=tost;
+  para.lenghtNoBr:=toend;
+  if res>0 then inc(toend); // there's a line break character - add it to the range
+  para.length:=toend;
+end;
+
 function WinInsertImageFromFile (const ARichMemo: TCustomRichMemo; APos: Integer;
    const FileNameUTF8: string;
    const AImgSize: TSize): Boolean;

components/richmemo/wsrichmemo.pas

@@ -80,6 +80,7 @@ type
       const AMetric: TIntParaMetric); virtual;
     class function GetParaNumbering(const AWinControl: TWinControl; TextStart: Integer;
       var ANumber: TIntParaNumbering): Boolean; virtual;
+    class function GetParaRange(const AWinControl: TWinControl; TextStart: Integer; var rng: TParaRange): Boolean; virtual;
     class procedure SetParaNumbering(const AWinControl: TWinControl; TextStart, TextLen: Integer;
       const ANumber: TIntParaNumbering); virtual;
     class procedure InDelText(const AWinControl: TWinControl; const TextUTF8: String; DstStart, DstLen: Integer); virtual;
@@ -167,6 +168,12 @@ begin
   Result := false;
 end;
 
+class function TWSCustomRichMemo.GetParaRange(const AWinControl: TWinControl;
+  TextStart: Integer; var rng: TParaRange): Boolean;
+begin
+  Result:=False;
+end;
+
 class procedure TWSCustomRichMemo.SetParaNumbering(
   const AWinControl: TWinControl; TextStart, TextLen: Integer;
   const ANumber: TIntParaNumbering);