lazarus/lcl/include/customlabel.inc

498 lines
14 KiB
PHP

{%MainUnit ../stdctrls.pp}
{******************************************************************************
TCustomLabel
******************************************************************************
*****************************************************************************
This file is part of the Lazarus Component Library (LCL)
See the file COPYING.modifiedLGPL.txt, included in this distribution,
for details about the license.
*****************************************************************************
TODO:
- Enable Tabbing/Focusing to focus FocusControl
- Enable Escaped '&' Shortcut to focus FocusControl
- Compare/Match AutoSize to Delphi/Kylix's
- ?? Check For Full Delphi/Kylix Compatibility
}
procedure TCustomLabel.CalculatePreferredSize(
var PreferredWidth, PreferredHeight: integer; WithThemeSpace: Boolean);
// assumes: (Parent <> nil) and Parent.HandleAllocated
var
AWidth: Integer;
begin
if (Parent = nil) or (not Parent.HandleAllocated) then Exit;
if WidthIsAnchored and WordWrap then
AWidth:=Width
else
AWidth:=10000;
AWidth:=Constraints.MinMaxWidth(AWidth);
CalculateSize(AWidth,PreferredWidth,PreferredHeight);
end;
procedure TCustomLabel.CalculateSize(MaxWidth: integer; var NeededWidth,
NeededHeight: integer);
var
DC: HDC;
R: TRect;
OldFont: HGDIOBJ;
Flags: cardinal;
LabelText: String;
begin
LabelText := GetLabelText;
if LabelText='' then begin
NeededWidth:=1;
NeededHeight:=1;
exit;
end;
DC := GetDC(Parent.Handle);
try
R := Rect(0, 0, MaxWidth, 10000);
OldFont := SelectObject(DC, HGDIOBJ(Font.Reference.Handle));
Flags := DT_CALCRECT or DT_EXPANDTABS;
if WordWrap then
Flags := Flags or DT_WORDBREAK
else
if not HasMultiLine then
Flags := Flags or DT_SINGLELINE;
if not ShowAccelChar then
Flags := Flags or DT_NOPREFIX;
DrawText(DC, PChar(LabelText), Length(LabelText), R, Flags);
SelectObject(DC, OldFont);
NeededWidth := R.Right - R.Left;
NeededHeight := R.Bottom - R.Top;
//DebugLn(['TCustomLabel.CalculatePreferredSize ',DbgSName(Self),' R=',dbgs(R),' MaxWidth=',MaxWidth,' DT_WORDBREAK=',(DT_WORDBREAK and Flags)>0,' LabelText="',LabelText,'"']);
finally
ReleaseDC(Parent.Handle, DC);
end;
end;
procedure TCustomLabel.FontChanged(Sender: TObject);
begin
inherited FontChanged(Sender);
UpdateSize;
end;
class function TCustomLabel.GetControlClassDefaultSize: TSize;
begin
Result.CX := 65;
Result.CY := 17;
end;
function TCustomLabel.HasMultiLine: boolean;
var
s: String;
begin
s := GetLabelText;
Result := (pos(#10, s) > 0) or (pos(#13, s) > 0);
end;
procedure TCustomLabel.DoAutoSize;
begin
inherited DoAutoSize;
//debugln('TCustomLabel.DoAutoSize ',DbgSName(Self),' AutoSizing=',dbgs(AutoSizing),' AutoSize=',dbgs(AutoSize),' Parent=',DbgSName(Parent),' csLoading=',dbgs(csLoading in ComponentState),' Parnet.HandleAllocated=',dbgs((Parent<>nil) and (Parent.HandleAllocated)));
end;
procedure TCustomLabel.SetAlignment(Value : TAlignment);
begin
//debugln('TCustomLabel.SetAlignment Old=',dbgs(ord(Alignment)),' New=',dbgs(ord(Value)),' csLoading=',dbgs(csLoading in ComponentState));
if FAlignment <> Value then
begin
FAlignment := Value;
Invalidate;
end;
end;
procedure TCustomLabel.Notification(AComponent : TComponent; Operation : TOperation);
begin
inherited Notification(AComponent, Operation);
if (AComponent = FFocusControl) and (Operation = opRemove) then
FFocusControl := nil;
end;
procedure TCustomLabel.SetFocusControl(Value : TWinControl);
begin
if Value <> FFocusControl then
begin
if FFocusControl <> nil then
FFocusControl.RemoveFreeNotification(Self);
FFocusControl:= Value;
if Value <> nil then
Value.FreeNotification(Self);
end;
end;
procedure TCustomLabel.WMActivate(var Message: TLMActivate);
begin
if (FFocusControl <> nil) and (FFocusControl.CanFocus) then
FFocusControl.SetFocus;
end;
function TCustomLabel.GetLabelText: string;
begin
Result := Caption;
end;
procedure TCustomLabel.SetShowAccelChar(Value : Boolean);
begin
if FShowAccelChar <> Value then
begin
FShowAccelChar := Value;
Invalidate;
UpdateSize;
end;
end;
procedure TCustomLabel.TextChanged;
begin
Invalidate;
UpdateSize;
end;
procedure TCustomLabel.DoSetBounds(ALeft, ATop, AWidth, AHeight: integer);
var
WidthChanged: Boolean;
begin
WidthChanged:=AWidth<>Width;
inherited DoSetBounds(ALeft, ATop, AWidth, AHeight);
if OptimalFill and (not AutoSize) then
AdjustFontForOptimalFill;
if WidthChanged and WordWrap then begin
InvalidatePreferredSize;
AdjustSize;
end;
end;
function TCustomLabel.CanTab: boolean;
begin
Result := False;
end;
procedure TCustomLabel.DoMeasureTextPosition(var TextTop: integer;
var TextLeft: integer);
var
lTextHeight: integer;
lTextWidth: integer;
begin
TextLeft := 0;
if Layout = tlTop then
begin
TextTop := 0;
end else
begin
CalculateSize(Width, lTextWidth, lTextHeight);
case Layout of
tlCenter: TextTop := (Height - lTextHeight) div 2;
tlBottom: TextTop := Height - lTextHeight;
end;
end;
end;
constructor TCustomLabel.Create(TheOwner: TComponent);
begin
inherited Create(TheOwner);
ControlStyle := [csCaptureMouse, csSetCaption, csClickEvents, csDoubleClicks, csReplicatable];
with GetControlClassDefaultSize do
SetInitialBounds(0, 0, CX, CY);
FShowAccelChar := True;
FInternalSetBounds := False;
Color := clNone;
AutoSize := True;
// Accessibility
AccessibleRole := larLabel;
end;
function TCustomLabel.GetTransparent: boolean;
begin
Result := Color = clNone;
end;
procedure TCustomLabel.SetColor(NewColor: TColor);
begin
inherited;
// if color = clnone then transparent, so not opaque
if NewColor = clNone then
ControlStyle := ControlStyle - [csOpaque]
else
ControlStyle := ControlStyle + [csOpaque];
end;
{------------------------------------------------------------------------------
Method: TCustomLabel.SetLayout
Params: None
Returns: Nothing
------------------------------------------------------------------------------}
procedure TCustomLabel.SetLayout(Value: TTextLayout);
begin
if FLayout <> Value then
begin
FLayout:= Value;
Invalidate;
end;
end;
procedure TCustomLabel.SetTransparent(NewTransparent: boolean);
begin
if Transparent = NewTransparent then
exit;
if NewTransparent then
Color := clNone
else
if Color = clNone then
Color := clBackground;
end;
{------------------------------------------------------------------------------
Method: TCustomLabel.SetWordWrap
Params: None
Returns: Nothing
------------------------------------------------------------------------------}
procedure TCustomLabel.SetWordWrap(Value: Boolean);
begin
if FWordWrap <> Value then
begin
FWordWrap := Value;
Invalidate;
UpdateSize;
end;
end;
function TCustomLabel.DialogChar(var Message: TLMKey): boolean;
begin
Result := False;
if not FShowAccelChar then exit;
if FFocusControl = nil then exit;
if IsAccel(Message.CharCode, GetLabelText) and FFocusControl.CanFocus then
begin
Result := True;
FFocusControl.SetFocus;
end else
Result := inherited DialogChar(Message);
end;
procedure TCustomLabel.Loaded;
begin
inherited Loaded;
AdjustSize;
end;
procedure TCustomLabel.UpdateSize;
begin
InvalidatePreferredSize;
if OptimalFill and (not AutoSize) then
AdjustFontForOptimalFill;
AdjustSize;
end;
{-------------------------------------------------------------------------------
function TCustomLabel.CalcFittingFontHeight(const TheText: string;
MaxWidth, MaxHeight: Integer;
var FontSize, NeededWidth, NeededHeight: integer): Boolean;
Calculates the maximum font size for TheText to fit into MaxWidth and
MaxHeight.
-------------------------------------------------------------------------------}
function TCustomLabel.CalcFittingFontHeight(const TheText: string;
MaxWidth, MaxHeight: Integer;
var FontHeight, NeededWidth, NeededHeight: integer): Boolean;
var
R : TRect;
DC : hDC;
Flags: Cardinal;
OldFont: HGDIOBJ;
MinFontHeight: Integer;
MaxFontHeight: Integer;
AFont: TFont;
CurFontHeight: LongInt;
begin
Result:=false;
if AutoSizeDelayed or (TheText='') or (MaxWidth<1) or (MaxHeight<1) then exit;
AFont:=TFont.Create;
AFont.Assign(Font);
CurFontHeight:=AFont.Height;
MinFontHeight:=5;
MaxFontHeight:=MaxHeight*2;
if (CurFontHeight<MinFontHeight) or (CurFontHeight>MaxFontHeight) then
CurFontHeight:=(MinFontHeight+MaxFontHeight) div 2;
Flags := DT_CALCRECT or DT_NOPREFIX or DT_EXPANDTABS;
if WordWrap then inc(Flags, DT_WORDBREAK);
// give a clipping rectangle with space, so that the bounds returned by
// DrawText can be bigger and we know, the tried font is too big.
R := Rect(0,0, MaxWidth, MaxHeight*2);
DC := GetDC(Parent.Handle);
try
while (MinFontHeight<=MaxFontHeight) and (CurFontHeight>=MinFontHeight)
and (CurFontHeight<=MaxFontHeight) do begin
AFont.Height:=CurFontHeight; // NOTE: some TFont do not allow any integer
//debugln('TCustomLabel.CalcFittingFontHeight A ',dbgs(MinFontHeight),'<=',dbgs(AFont.Height),'<=',dbgs(MaxFontHeight));
OldFont := SelectObject(DC, HGDIOBJ(AFont.Reference.Handle));
DrawText(DC, PChar(TheText), Length(TheText), R, Flags);
SelectObject(DC, OldFont);
NeededWidth := R.Right - R.Left;
NeededHeight := R.Bottom - R.Top;
//debugln('TCustomLabel.CalcFittingFontHeight B NeededWidth=',dbgs(NeededWidth),' NeededHeight=',dbgs(NeededHeight),' MaxWidth=',dbgs(MaxWidth),' MaxHeight=',dbgs(MaxHeight));
if (NeededWidth>0) and (NeededHeight>0)
and (NeededWidth<=MaxWidth) and (NeededHeight<=MaxHeight) then begin
// TheText fits into the bounds
if (not Result) or (FontHeight<AFont.Height) then
FontHeight:=AFont.Height;
Result:=true;
MinFontHeight:=CurFontHeight;
// -> try bigger (binary search)
CurFontHeight:=(MaxFontHeight+CurFontHeight+1) div 2; // +1 to round up
if CurFontHeight=MinFontHeight then break;
end else begin
// TheText does not fit into the bounds
MaxFontHeight:=CurFontHeight-1;
// -> try smaller (binary search)
CurFontHeight:=(MinFontHeight+CurFontHeight) div 2;
end;
end
finally
ReleaseDC(Parent.Handle, DC);
AFont.Free;
end;
end;
function TCustomLabel.ColorIsStored: boolean;
begin
Result := (Color <> clNone);
end;
{-------------------------------------------------------------------------------
function TCustomLabel.AdjustFontForOptimalFill: Boolean;
Maximizes Font.Height
Return true if Font.Height changed.
-------------------------------------------------------------------------------}
function TCustomLabel.AdjustFontForOptimalFill: Boolean;
var
NeededWidth: Integer;
NeededHeight: Integer;
NewFontHeight: Integer;
OldFontHeight: LongInt;
begin
Result := False;
if not CalcFittingFontHeight(GetLabelText, Width, Height, NewFontHeight,
NeededWidth, NeededHeight) then Exit;
if Font.Height = NewFontHeight then Exit;
//debugln('TCustomLabel.AdjustFontForOptimalFill OldFontHeight=',dbgs(Font.Height),' NewFontHeight=',dbgs(NewFontHeight));
OldFontHeight := Font.Height;
Font.Height := NewFontHeight;
Result := OldFontHeight <> Font.Height;
end;
procedure TCustomLabel.Paint;
var
TR : TTextStyle;
R : TRect;
TextLeft, TextTop: integer;
LabelText: string;
OldFontColor: TColor;
begin
R := Rect(0,0,Width,Height);
with Canvas do
begin
Brush.Color := Self.Color;
if (Color<>clNone) and not Transparent then
begin
Brush.Style:=bsSolid;
FillRect(R);
end;
Brush.Style:=bsClear;
Font := Self.Font;
{
If BorderStyle <> sbsNone then begin
InflateRect(R,-2,-2);
Pen.Style := psSolid;
If BorderStyle = sbsSunken then
Pen.Color := clBtnShadow
else
Pen.Color := clBtnHighlight;
MoveTo(0, 0);
LineTo(Width - 1,0);
MoveTo(0, 0);
LineTo(0,Height - 1);
If BorderStyle = sbsSunken then
Pen.Color := clBtnHighlight
else
Pen.Color := clBtnShadow;
MoveTo(0,Height - 1);
LineTo(Width - 1,Height - 1);
MoveTo(Width - 1, 0);
LineTo(Width - 1,Height);
end;
}
//Brush.Color:=clRed;
//FillRect(R);
FillChar(TR,SizeOf(TR),0);
with TR do
begin
Alignment := BidiFlipAlignment(Self.Alignment, UseRightToLeftAlignment);
Layout := Self.Layout;
Opaque := (Color<>clNone) and not Transparent;
WordBreak := wordWrap;
SingleLine:= not WordWrap and not HasMultiLine;
Clipping := True;
ShowPrefix := ShowAccelChar;
SystemFont := False;
RightToLeft := UseRightToLeftReading;
ExpandTabs := True;
end;
DoMeasureTextPosition(TextTop, TextLeft);
//debugln('TCustomLabel.Paint ',dbgs(Alignment=tacenter),' ',dbgs(Layout=tlCenter),' ',dbgs(TextLeft),' TextTop=',dbgs(TextTop),' ',dbgs(R));
LabelText := GetLabelText;
OldFontColor := Font.Color;
if not IsEnabled then
begin
Font.Color := clBtnHighlight;
TextRect(R, TextLeft + 1, TextTop + 1, LabelText, TR);
Font.Color := clBtnShadow;
end;
TextRect(R, TextLeft, TextTop, LabelText, TR);
Font.Color := OldFontColor;
end;
end;
procedure TCustomLabel.SetBounds(aLeft, aTop, aWidth, aHeight: integer);
begin
if (Left=aLeft) and (Top=aTop) and (Width=aWidth) and (Height=aHeight) then exit;
if not FInternalSetBounds and AutoSize and WordWrap then
InvalidatePreferredSize;
inherited SetBounds(aLeft, aTop, aWidth, aHeight);
end;
procedure TCustomLabel.SetOptimalFill(const AValue: Boolean);
begin
if FOptimalFill = AValue then Exit;
FOptimalFill := AValue;
if OptimalFill and AutoSize then
AutoSize := False;
Invalidate;
end;
class procedure TCustomLabel.WSRegisterClass;
begin
inherited WSRegisterClass;
RegisterCustomLabel;
RegisterPropertyToSkip(TCustomLabel, 'EllipsisPosition', 'VCL compatibility property', '');
end;
// included by stdctrls.pp