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|
Unit RichTextLayoutUnit;
{$mode objfpc}{$H+}
// Dynamically created layout class.
// Represents a laid out rich text document
Interface
Uses
Classes,
CanvasFontManager,
RichTextDocumentUnit,
RichTextStyleUnit,
fpg_imagelist,
contnrs;
Type
TLayoutLine = class(TObject)
public
Text: PChar;
Length: longint;
Height: longint;
Width: longint;
MaxAscender: longint;
MaxDescender: longint;
MaxTextHeight: longint; // maximum height of text, doesn't include images
LinkIndex: longint; // link index at start of line, if any
Style: TTextDrawStyle;
Wrapped: boolean;
end;
TLayoutLineList = class(TObjectList)
protected
function GetItem(Index: Integer): TLayoutLine; reintroduce;
procedure SetItem(Index: Integer; const AValue: TLayoutLine); reintroduce;
public
function Add(AObject: TLayoutLine): Integer; reintroduce;
function Remove(AObject: TLayoutLine): Integer; reintroduce;
function IndexOf(AObject: TLayoutLine): Integer; reintroduce;
function First: TLayoutLine; reintroduce;
Function Last: TLayoutLine; reintroduce;
property Items[Index: Integer]: TLayoutLine read GetItem write SetItem; default;
end;
TTextPosition = (
tpAboveTextArea,
tpAboveText,
tpWithinText,
tpBelowText,
tpBelowTextArea
);
// forward declaration
TRichTextLayout = class;
// TLinkEvent = procedure( Sender: TRichTextLayout; Link: string ) of object;
TRichTextLayout = class(TObject)
Protected
FFontManager: TCanvasFontManager;
FText: PChar;
FImages: TfpgImageList;
FLayoutWidth: longint; // The target width for the layout. Used for centreing/right align
FWidth: longint; // The actual width of the text. May be wider due to unaligned
// parts or bitmaps or width so small individual characters don't fit.
FHeight: longint;
FLinks: TStringList;
FHorizontalImageScale: double;
FVerticalImageScale: double;
public
FLines: TLayoutLineList;
FNumLines: longint;
FRichTextSettings: TRichTextSettings;
// Drawing functions
Procedure PerformStyleTag( Const Tag: TTag;
Var Style: TTextDrawStyle;
const X: longint );
function GetElementWidth( Element: TTextElement ): longint;
// Queries
Function GetStartX( Style: TTextDrawStyle; Line: TLayoutLine ): longint;
Procedure GetXFromOffset( const Offset: longint;
const LineIndex: longint;
Var X: longint );
Procedure GetOffsetFromX( const XToFind: longint;
const LineIndex: longint;
Var Offset: longint;
Var Link: string );
function FindPoint( XToFind, YToFind: longint;
Var LineIndex: longint;
Var Offset: longint;
Var Link: string ): TTextPosition;
function GetLineFromCharIndex( Index: longint ): longint;
function GetOffsetFromCharIndex( Index: longint;
Line: longint ): longint;
function GetLinePosition( Line: longint ): longint;
function GetLineFromPosition( YToFind: longint;
Var LineIndex: longint;
Var Remainder: longint ): TTextPosition;
// Layout functions
Procedure AddLineStart(var Line: TLayoutLine);
Procedure CheckFontHeights(var Line: TLayoutLine);
Procedure Layout;
function IsValidBitmapIndex( Index: longint ): boolean;
// property handlers
Function GetCharIndex( P: PChar ): longint;
Function GetTextEnd: longint;
public
constructor Create(Text: PChar; Images: TfpgImageList; RichTextSettings: TRichTextSettings; FontManager: TCanvasFontManager; AWidth: longint);
destructor Destroy; Override;
function LinkFromIndex( const CharIndexToFind: longint): string;
property TextEnd: longint read GetTextEnd;
property Images: TfpgImageList read FImages;
property Width: longint read FWidth;
property Height: longint read FHeight;
property HorizontalImageScale: double read FHorizontalImageScale;
property VerticalImageScale: double read FVerticalImageScale;
end;
implementation
uses
SysUtils,
ACLStringUtility,
nvUtilities,
fpg_main;
{ TLayoutLineList }
function TLayoutLineList.GetItem(Index: Integer): TLayoutLine;
begin
result := TLayoutLine( inherited GetItem(Index));
end;
procedure TLayoutLineList.SetItem(Index: Integer; const AValue: TLayoutLine);
begin
inherited SetItem(Index, AValue);
end;
function TLayoutLineList.Add(AObject: TLayoutLine): Integer;
begin
Result := inherited Add(AObject);
end;
function TLayoutLineList.Remove(AObject: TLayoutLine): Integer;
begin
Result := inherited Remove(AObject);
end;
function TLayoutLineList.IndexOf(AObject: TLayoutLine): Integer;
begin
Result := inherited IndexOf(AObject);
end;
function TLayoutLineList.First: TLayoutLine;
begin
Result := TLayoutLine(inherited First);
end;
function TLayoutLineList.Last: TLayoutLine;
begin
Result := TLayoutLine(inherited Last);
end;
{ TRichTextLayout }
Function TRichTextLayout.GetTextEnd: longint;
begin
Result := StrLen( FText );
end;
// Create a layout of the specified rich text.
constructor TRichTextLayout.Create(Text: PChar; Images: TfpgImageList;
RichTextSettings: TRichTextSettings; FontManager: TCanvasFontManager;
AWidth: longint);
begin
ProfileEvent('DEBUG: TRichTextLayout.Create >>>>');
inherited Create;
FRichTextSettings := RichTextSettings;
FImages := Images;
FText := Text;
FLines := TLayoutLineList.Create;
FNumLines := 0;
FLinks := TStringList.Create;
FLinks.Duplicates := dupIgnore;
FFontManager := FontManager;
FLayoutWidth := AWidth;
FHorizontalImageScale := 1;
FVerticalImageScale := 1;
//FHorizontalImageScale := FFontManager.Canvas.HorizontalResolution
// / Screen.Canvas.HorizontalResolution;
//FVerticalImageScale := FFontManager.Canvas.VerticalResolution
// / Screen.Canvas.VerticalResolution;
Layout;
ProfileEvent('DEBUG: TRichTextLayout.Create <<<<');
end;
Destructor TRichTextLayout.Destroy;
Begin
ProfileEvent('TRichTextLayout.Destroy ******* ');
FreeAndNil(FLines);
FLinks.Free;
FRichTextSettings := nil; // was a reference only
FImages := nil; // was a reference only
FFontManager := nil; // was a reference only
inherited Destroy;
End;
Procedure TRichTextLayout.AddLineStart(var Line: TLayoutLine);
begin
FLines.Add(Line);
inc( FNumLines );
ProfileEvent('TRichTextLayout.AddLineStart: FNumLines =' + intToStr(FNumLines));
end;
Procedure TRichTextLayout.PerformStyleTag( Const Tag: TTag;
Var Style: TTextDrawStyle;
const X: longint );
begin
ProfileEvent('TRichTextLayout.PerformStyleTag >>>');
ApplyStyleTag( Tag,
Style,
FFontManager,
FRichTextSettings,
X );
ProfileEvent('TRichTextLayout.PerformStyleTag <<<');
end;
// Check the current font specifications and see if the
// given line needs updating for max height/descender
Procedure TRichTextLayout.CheckFontHeights( Var Line: TLayoutLine );
var
FontHeight: longint;
Descender: longint;
Ascender: longint;
begin
FontHeight := FFontManager.CharHeight;
Ascender := FFontManager.CharAscender;
Descender := FFontManager.CharDescender;
if FontHeight > Line.Height then
Line.Height := FontHeight;
if FontHeight > Line.MaxTextHeight then
Line.MaxTextHeight := FontHeight;
if Descender > Line.MaxDescender then
Line.MaxDescender := Descender;
if Ascender > Line.MaxAscender then
Line.MaxAscender := Ascender;
end;
function TRichTextLayout.IsValidBitmapIndex( Index: longint ): boolean;
begin
if FImages = nil then
Result := false
else if FImages.Count = 0 then
Result := false
else
Result := Between( Index, 0, FImages.Count - 1 );
end;
// Main procedure: reads through the whole text currently stored
// and breaks up into lines - each represented as a TLayoutLine in
// the LayoutLineList class
Procedure TRichTextLayout.Layout;
Var
CurrentLine: TLayoutLine;
CurrentLinkIndex: longint;
WrapX: longint; // X to wrap at
WordX: longint; // width of the current word so far
P: PChar;
NextP: PChar;
NextP2: PChar;
WordStart: PChar;
WordStarted: boolean; // if false, just skipping spaces..
WordStartX: longint; // X position of word start
LineWordsCompleted: longint; // how many words draw so far this line
CurrentElement: TTextElement;
NextElement: TTextElement;
CurrentCharWidth: longint;
Style: TTextDrawStyle;
DisplayedCharsSinceFontChange: boolean;
BitmapIndex: longint;
Bitmap: TfpgImage;
BitmapHeight: longint;
OnBreak: boolean;
DoWrap: boolean;
// Nested procedure
procedure CreateDefaultCurrentLine;
begin
CurrentLine := TLayoutLine.Create;
CurrentLine.Style := Style;
CurrentLine.Height := 0;
CurrentLine.MaxAscender := 0;
CurrentLine.MaxDescender := 0;
CurrentLine.MaxTextHeight := 0;
CurrentLine.Width := 0;
CurrentLine.LinkIndex := CurrentLinkIndex;
CurrentLine.Wrapped := false;
end;
Procedure DoLine( EndPoint: PChar; NextLine: PChar; EndX: longint );
begin
// check if the max font
// height needs updating for the last string of the line
CheckFontHeights( CurrentLine );
inc( FHeight, CurrentLine.Height );
CurrentLine.Length := PCharDiff( EndPoint, CurrentLine.Text );
CurrentLine.Width := EndX;
if CurrentLine.Width > FWidth then
FWidth := CurrentLine.Width;
Assert( CurrentLine.Height > 0 ); // we must have set the line height!
AddLineStart( CurrentLine );
CreateDefaultCurrentLine;
CurrentLine.Text := NextLine;
assert( CurrentLinkIndex >= -1 );
assert( CurrentLinkIndex < FLinks.Count );
WordStartX := Style.LeftMargin;
// next line
// reset words completed count
LineWordsCompleted := 0;
WordStarted := false;
end;
begin
ProfileEvent('DEBUG: TRichTextLayout.Layout >>>>');
FNumLines := 0;
FWidth := FRichTextSettings.Margins.Left;
FHeight := FRichTextSettings.Margins.Top;
Style := GetDefaultStyle( FRichTextSettings );
ApplyStyle( Style, FFontManager );
CurrentLinkIndex := -1;
WordStartX := Style.LeftMargin;
WordX := 0;
WrapX := FLayoutWidth - FRichTextSettings.Margins.Right;
LineWordsCompleted := 0;
WordStarted := false;
DisplayedCharsSinceFontChange := false;
P := FText; // P is the current search position
if FText = '' then
exit;
CreateDefaultCurrentLine;
CurrentLine.Text := P;
repeat
CurrentElement := ExtractNextTextElement( P, NextP );
assert( NextP > P );
OnBreak := false;
case CurrentElement.ElementType of
teWordBreak:
begin
CurrentCharWidth := FFontManager.CharWidth( ' ' );
OnBreak := true;
end;
teLineBreak:
begin
DoLine( P, NextP, WordStartX + WordX );
// remember start of line
WordStart := NextP;
WordX := 0;
P := NextP;
continue;
end;
teTextEnd:
begin
DoLine( P, NextP, WordStartX + WordX );
// end of text, so it is safe to free CurrentLine created in DoLine()
CurrentLine.Free;
break;
end;
teImage:
begin
BitmapHeight := 0;
try
BitmapIndex := StrToInt( CurrentElement.Tag.Arguments );
except
BitmapIndex := -1;
end;
Bitmap := nil;
if IsValidBitmapIndex( BitmapIndex ) then
begin
Bitmap := FImages.Items[BitmapIndex].Image;
CurrentCharWidth := Trunc(Bitmap.Width * FHorizontalImageScale);
WordStarted := true;
BitmapHeight := Trunc(Bitmap.Height * FVerticalImageScale);
end;
end;
teText:
begin
// Normal (non-leading-space) character
CurrentCharWidth := FFontManager.CharWidth( CurrentElement.Character );
WordStarted := true;
end;
teStyle:
begin
case CurrentElement.Tag.TagType of
ttBeginLink:
begin
CurrentLinkIndex := FLinks.Add( CurrentElement.Tag.Arguments );
P := NextP;
continue;
end;
ttEndLink:
begin
CurrentLinkIndex := -1;
P := NextP;
continue;
end;
ttSetLeftMargin: // SPECIAL CASE... could affect display immediately
begin
PerformStyleTag( CurrentElement.Tag, Style, WordstartX + WordX );
if Style.LeftMargin < WordStartX then
begin
// we're already past the margin being set
if pos( 'breakifpast', CurrentElement.Tag.Arguments ) > 0 then
begin
// this argument means, do a line break
// if the margin is already past
// Seems unusual for most purposes, but needed for IPF rendering.
DoLine( P, NextP, WordStartX + WordX );
// remember start of line
WordStart := NextP;
WordX := 0;
P := NextP;
continue;
end;
// so ignore it for now.
P := NextP;
continue;
end;
// skip across to the new margin
CurrentCharWidth := Style.LeftMargin - WordStartX - WordX;
// BUT! Don't treat it as a space, because you would not
// expect wrapping to take place in a margin change...
// at least not for IPF :)
end; { teSetLeftMargin }
else
begin
// before processing the tag see if font height needs updating
if DisplayedCharsSinceFontChange then
CheckFontHeights( CurrentLine );
if ( CurrentElement.Tag.TagType = ttItalicOff )
and ( faItalic in Style.FontAttributes ) then
begin
if not FFontManager.IsFixed then
begin
// end of italic; add a space
// inc( WordX, FFontManager.CharWidth( ' ' ) );
end;
end;
PerformStyleTag( CurrentElement.Tag, Style, WordX );
DisplayedCharsSinceFontChange := false;
P := NextP;
continue; // continue loop
end;
end; { case CurrentElement.Tag.TagType of... }
end { teStyle }
end; { case CurrentElement.ElementType of... }
if OnBreak then
begin
// we just processed a space
if WordStarted then
begin
DisplayedCharsSinceFontChange := true;
// remember that we have now completed a word on this line
inc( LineWordsCompleted );
WordStarted := false;
// Add the word width, and the space width,
// to get the start of the next word
inc( WordStartX, WordX + CurrentCharWidth );
WordX := 0;
// remember the start of the next word
WordStart := NextP;
P := NextP;
continue;
end;
// else - starting spaces - fall through like normal char
end;
// if we're still going here we have a normal char
// (or leading spaces)
if not Style.Wrap then
begin
// No alignment
// We don't care about how wide it gets
inc( WordX, CurrentCharWidth );
DisplayedCharsSinceFontChange := true;
if CurrentElement.ElementType = teImage then
if Bitmap <> nil then
if BitmapHeight > CurrentLine.Height then
CurrentLine.Height := BitmapHeight;
P := NextP;
continue;
end;
DoWrap := false;
// Calculate position of end of character
// see if char would exceed width
if (WordStartX + WordX + CurrentCharWidth) >= WrapX then
begin
// reached right hand side before finding end of word
if LineWordsCompleted > 0 then
// always wrap after at least one word displayed
DoWrap := true
else if not FRichTextSettings.AtLeastOneWordBeforeWrap then
// only wrap during the first word, if the "at least 1 word" flag is not set.
DoWrap := true;
end;
if DoWrap then
begin
if LineWordsCompleted = 0 then
begin
// the first word did not fit on the line. so draw
// as much as will fit
if WordX = 0 then
begin
// even the first char doesn't fit,
// but draw it anyway (otherwise, infinite loop)
NextElement := ExtractNextTextElement( NextP, NextP2 );
if NextElement.ElementType <> teLineBreak then
// there is still more on the line...
CurrentLine.Wrapped := true
else
// the line ends after this one char or image, we can skip the line end
NextP := NextP2;
if CurrentElement.ElementType = teImage then
begin
// the only thing on the line is the image. so check height
if Bitmap <> nil then
if BitmapHeight > CurrentLine.Height then
CurrentLine.Height := BitmapHeight;
end;
DoLine( NextP, NextP, WordStartX + WordX + CurrentCharWidth );
WordStart := NextP;
WordX := 0;
end
else
begin
CurrentLine.Wrapped := true;
// at least 1 char fits
// so draw up to, but not including this char
DoLine( P,
P,
WordStartX + WordX );
WordStart := P;
WordX := CurrentCharWidth;
end;
end
else
begin
// Normal wrap; at least one word fitted on the line
CurrentLine.Wrapped := true;
// take the width of the last space of the
// previous word off the line width
DoLine( WordStart, // current line ends at start of this word
WordStart, // next line starts at start of this word
WordStartX - FFontManager.CharWidth( ' ' ) );
if CurrentElement.ElementType = teImage then
if Bitmap <> nil then
if BitmapHeight > CurrentLine.Height then
CurrentLine.Height := BitmapHeight;
// do NOT reset WordX to zero; as we are continuing
// from partway thru the word on the next line.
inc( WordX, CurrentCharWidth );
end;
WordStarted := true; // by definition, for wrapping
end
else
begin
// Character fits.
inc( WordX, CurrentCharWidth );
DisplayedCharsSinceFontChange := true;
if CurrentElement.ElementType = teImage then
if Bitmap <> nil then
if BitmapHeight > CurrentLine.Height then
CurrentLine.Height := BitmapHeight;
end;
P := NextP;
until false; // loop is exited by finding end of text
inc( FHeight, FRichTextSettings.Margins.Bottom );
ProfileEvent('DEBUG: TRichTextLayout.Layout <<<<');
End;
Function TRichTextLayout.GetStartX( Style: TTextDrawStyle;
Line: TLayoutLine ): longint;
var
SpaceOnLine: longint;
begin
case Style.Alignment of
taLeft:
Result := Style.LeftMargin;
taRight:
Result := Style.LeftMargin + FLayoutWidth
- Style.RightMargin - Line.Width;
taCenter:
begin
// |<------layout width------------------>|
// | |
// |<-lm->[aaaaaaaaaaaaaaa]<-space-><-rm->|
// |<-----line width------> |
// space = layoutw-rm-linew
SpaceOnLine := FLayoutWidth - Style.RightMargin - Line.Width; // Note: line width includes left margin
Result := Style.LeftMargin + (SpaceOnLine div 2);
end;
end;
end;
Procedure TRichTextLayout.GetOffsetFromX( const XToFind: longint;
const LineIndex: longint;
Var Offset: longint;
Var Link: string );
Var
X: longint;
P: PChar;
NextP: PChar;
EndP: PChar;
Element: TTextElement;
CurrentLink: string;
Line: TLayoutLine;
Style: TTextDrawStyle;
NewMarginX: longint;
StartedDrawing: boolean;
fstyle: string;
begin
Line := FLines[LineIndex];
P := Line.Text;
EndP := Line.Text + Line.Length;
Style := Line.Style;
fStyle := Style.FontNameSize;
ApplyFontAttributes(fStyle, Style.FontAttributes);
FFontManager.SetFont( fStyle );
StartedDrawing := false;
Link := '';
if Line.LinkIndex <> -1 then
CurrentLink := FLinks[ Line.LinkIndex ]
else
CurrentLink := '';
while P < EndP do
begin
Element := ExtractNextTextElement( P, NextP );
case Element.ElementType of
teWordBreak,
teText,
teImage:
begin
if not StartedDrawing then
begin
// we haven't yet started drawing:
// so work out alignment
X := GetStartX( Style, Line );
if X > XToFind then
begin
// found before the start of the line
// don't set link
Offset := 0;
exit;
end;
StartedDrawing := true;
end;
// Now find out how wide the thing is
inc( X, GetElementWidth( Element ) );
if X > XToFind then
begin
// found
Offset := PCharDiff( P, Line.Text );
Link := CurrentLink;
exit;
end;
end;
teStyle:
case Element.Tag.TagType of
ttBeginLink:
CurrentLink := Element.Tag.Arguments;
ttEndLink:
CurrentLink := '';
else
begin
if ( Element.Tag.TagType = ttItalicOff )
and ( faItalic in Style.FontAttributes )
and ( not FFontManager.IsFixed ) then
// end of italic; add a space
// inc( X, FFontManager.CharWidth( ' ' ) );
PerformStyleTag( Element.Tag, Style, X );
NewMarginX := Style.LeftMargin;
if NewMarginX > X then
begin
//skip across...
X := NewMarginX;
end;
end;
end;
end;
P := NextP;
end;
Offset := Line.Length;
end;
Procedure TRichTextLayout.GetXFromOffset( const Offset: longint;
const LineIndex: longint;
Var X: longint );
Var
P: PChar;
NextP: PChar;
EndP: PChar;
Element: TTextElement;
StartedDrawing: boolean;
Line: TLayoutLine;
Style: TTextDrawStyle;
NewMarginX: longint;
fStyle: string;
begin
Line := FLines[LineIndex];
P := Line.Text;
EndP := Line.Text + Line.Length;
Style := Line.Style;
fStyle := Style.FontNameSize;
ApplyFontAttributes(fStyle, Style.FontAttributes);
FFontManager.SetFont( fStyle );
StartedDrawing := false;
while P < EndP do
begin
Element := ExtractNextTextElement( P, NextP );
case Element.ElementType of
teWordBreak,
teText,
teImage:
begin
if not StartedDrawing then
begin
// we haven't yet started drawing:
// so work out alignment
X := GetStartX( Style, Line );
StartedDrawing := true;
end;
if GetCharIndex( P ) - GetCharIndex( Line.Text ) >= Offset then
begin
// found
exit;
end;
// Now find out how wide the thing is
inc( X, GetElementWidth( Element ) );
end;
teStyle:
begin
if ( Element.Tag.TagType = ttItalicOff )
and ( faItalic in Style.FontAttributes )
and ( not FFontManager.IsFixed ) then
// end of italic; add a space
// inc( X, FFontManager.CharWidth( ' ' ) );
PerformStyleTag( Element.Tag, Style, X );
NewMarginX := Style.LeftMargin;
if NewMarginX > X then
begin
//skip across...
X := NewMarginX;
end;
end;
end;
P := NextP;
end;
// went thru the whole line without finding the point,
if not StartedDrawing then
X := GetStartX( Style, Line );
end;
function TRichTextLayout.GetLineFromPosition( YToFind: longint;
Var LineIndex: longint;
Var Remainder: longint ): TTextPosition;
var
Y: longint;
LineHeight: longint;
begin
LineIndex := 0;
Remainder := 0;
Y := FRichTextSettings.Margins.Top;
if YToFind < Y then
begin
Result := tpAboveText;
Exit; //==>
end;
// TODO: Replace FNumLines with FLines.Count-1
while LineIndex < FNumLines do
begin
LineHeight := FLines[LineIndex].Height;
if ( YToFind >= Y )
and ( YToFind < (Y + LineHeight)) then
begin
// YToFind is within the line
Result := tpWithinText;
Remainder := YToFind - Y;
exit;
end;
inc( Y, LineHeight );
inc( LineIndex );
end;
LineIndex := FNumLines - 1;
{ check for a valid range }
if (LineIndex < 0) or (LineIndex > FLines.Count-1) then
Remainder := 0
else
Remainder := FLines[LineIndex].Height;
Result := tpBelowText;
end;
function TRichTextLayout.FindPoint( XToFind, YToFind: longint;
Var LineIndex: longint;
Var Offset: longint;
Var Link: string ): TTextPosition;
var
Remainder: longint;
begin
Link := '';
Result := GetLineFromPosition(YToFind, LineIndex, Remainder);
case Result of
tpAboveText:
begin
Offset := 0;
exit;
end;
tpBelowText:
begin
Offset := FLines[LineIndex].Length;
exit;
end;
end;
// found the line
GetOffsetFromX( XToFind,
LineIndex,
Offset,
Link );
end;
function TRichTextLayout.GetLineFromCharIndex( Index: longint ): longint;
var
LineCharIndex: longint;
LineLength: longint;
begin
Result := 0;
if Index <= 0 then
Exit; //==>
while Result < FNumLines do
begin
LineCharIndex := GetCharIndex(FLines[Result].Text );
LineLength := FLines[Result].Length;
if (LineCharIndex + LineLength) > Index then
begin
// found
Exit; //==>
end;
inc( Result );
end;
Result := FNumLines - 1;
end;
function TRichTextLayout.GetOffsetFromCharIndex( Index: longint;
Line: longint ): longint;
begin
Result := Index - GetCharIndex(FLines[Line].Text);
end;
function TRichTextLayout.GetElementWidth( Element: TTextElement ): longint;
var
Bitmap: TfpgImage;
BitmapIndex: longint;
begin
// Now find out how wide the thing is
case Element.ElementType of
teImage:
begin
try
BitmapIndex := StrToInt( Element.Tag.Arguments );
except
BitmapIndex := -1;
end;
if IsValidBitmapIndex( BitmapIndex ) then
begin
Bitmap := FImages.Items[BitmapIndex].Image;
Result := Trunc(Bitmap.Width * FHorizontalImageScale);
end;
end;
teText, teWordBreak:
Result := FFontManager.CharWidth( Element.Character );
else
Assert( False ); // should never be trying to find the width of a style, etc
end;
end;
Function TRichTextLayout.GetCharIndex( P: PChar ): longint;
begin
Result := PCharDiff( P, FText );
end;
function TRichTextLayout.GetLinePosition( Line: longint ): longint;
begin
Result := FRichTextSettings.Margins.Top;
dec( line );
while line >= 0 do
begin
inc( Result, Flines[Line].Height );
dec( line );
end;
end;
function TRichTextLayout.LinkFromIndex( const CharIndexToFind: longint): string;
Var
P: PChar;
NextP: PChar;
EndP: PChar;
Element: TTextElement;
LineIndex: longint;
Line: TLayoutLine;
begin
if FNumLines = 0 then
begin
Result := '';
Exit; //==>
end;
LineIndex := GetLineFromCharIndex( CharIndexToFind );
Line := FLines[LineIndex];
P := Line.Text;
EndP := Line.Text + Line.Length;
if Line.LinkIndex <> -1 then
Result := FLinks[ Line.LinkIndex ]
else
Result := '';
while P < EndP do
begin
if GetCharIndex( P ) >= CharIndexToFind then
exit;
Element := ExtractNextTextElement( P, NextP );
case Element.ElementType of
teStyle:
case Element.Tag.TagType of
ttBeginLink:
Result := Element.Tag.Arguments;
ttEndLink:
Result := '';
end;
end;
P := NextP;
end;
end;
end.
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