xpgraphutil.pas

xpbutton是一個delphi的按鈕套件,可以更改字體的顏色及字型

{
 Copyright:      rhoStyle   
 mailto:	 [e-mail]
 Author:         rhoStyle developers group 
 Remarks:        freeware
 known Problems: none
 Version:        1.0
 Delphi Version: Delphi 3-7
 Description:    This is utility unit for Windows XP style controls

}
unit XPGraphUtil;


interface

uses
  Windows, Graphics;

type
  TFillDirection = (fdTopToBottom, fdBottomToTop, fdLeftToRight, fdRightToLeft);

procedure GradientFillRect(Canvas: TCanvas; ARect: TRect; StartColor,
  EndColor: TColor; Direction: TFillDirection; Colors: Byte);

procedure GradientVertLine (Canvas : TCanvas; X, Y, Len : Integer; StartColor,
  EndColor: TColor; Direction: TFillDirection; Colors: Byte);

function WidthOf(R: TRect): Integer;  
function HeightOf(R: TRect): Integer;


implementation

function Max (Value1, Value2 : Integer) : Integer;
begin
  If Value1 > Value2 then Result := Value1 else Result := Value2;
end;

function Min (Value1, Value2 : Integer) : Integer;
begin
  If Value1 < Value2 then Result := Value1 else Result := Value2;
end;

function HeightOf(R: TRect): Integer;
begin
  Result := R.Bottom - R.Top;
end;

function WidthOf(R: TRect): Integer;
begin
  Result := R.Right - R.Left;
end;


procedure GradientFillRect(Canvas: TCanvas; ARect: TRect; StartColor,
  EndColor: TColor; Direction: TFillDirection; Colors: Byte);
var
  StartRGB: array[0..2] of Byte;    { Start RGB values }
  RGBDelta: array[0..2] of Integer; { Difference between start and end RGB values }
  ColorBand: TRect;                 { Color band rectangular coordinates }
  I, Delta: Integer;
  Brush: HBrush;
begin
  if IsRectEmpty(ARect) then Exit;
  if Colors < 2 then begin
    Brush := CreateSolidBrush(ColorToRGB(StartColor));
    FillRect(Canvas.Handle, ARect, Brush);
    DeleteObject(Brush);
    Exit;
  end;
  StartColor := ColorToRGB(StartColor);
  EndColor := ColorToRGB(EndColor);
  case Direction of
    fdTopToBottom, fdLeftToRight: begin
      { Set the Red, Green and Blue colors }
      StartRGB[0] := GetRValue(StartColor);
      StartRGB[1] := GetGValue(StartColor);
      StartRGB[2] := GetBValue(StartColor);
      { Calculate the difference between begin and end RGB values }
      RGBDelta[0] := GetRValue(EndColor) - StartRGB[0];
      RGBDelta[1] := GetGValue(EndColor) - StartRGB[1];
      RGBDelta[2] := GetBValue(EndColor) - StartRGB[2];
    end;
    fdBottomToTop, fdRightToLeft: begin
      { Set the Red, Green and Blue colors }
      { Reverse of TopToBottom and LeftToRight directions }
      StartRGB[0] := GetRValue(EndColor);
      StartRGB[1] := GetGValue(EndColor);
      StartRGB[2] := GetBValue(EndColor);
      { Calculate the difference between begin and end RGB values }
      { Reverse of TopToBottom and LeftToRight directions }
      RGBDelta[0] := GetRValue(StartColor) - StartRGB[0];
      RGBDelta[1] := GetGValue(StartColor) - StartRGB[1];
      RGBDelta[2] := GetBValue(StartColor) - StartRGB[2];
    end;
  end; {case}
  { Calculate the color band's coordinates }
  ColorBand := ARect;
  if Direction in [fdTopToBottom, fdBottomToTop] then begin
    Colors := Max(2, Min(Colors, HeightOf(ARect)));
    Delta := HeightOf(ARect) div Colors;
  end
  else begin
    Colors := Max(2, Min(Colors, WidthOf(ARect)));
    Delta := WidthOf(ARect) div Colors;
  end;
  with Canvas.Pen do begin { Set the pen style and mode }
    Style := psSolid;
    Mode := pmCopy;
  end;
  { Perform the fill }
  if Delta > 0 then begin
    for I := 0 to Colors do begin
      case Direction of
        { Calculate the color band's top and bottom coordinates }
        fdTopToBottom, fdBottomToTop: begin
          ColorBand.Top := ARect.Top + I * Delta;
          ColorBand.Bottom := ColorBand.Top + Delta;
        end;
        { Calculate the color band's left and right coordinates }
        fdLeftToRight, fdRightToLeft: begin
          ColorBand.Left := ARect.Left + I * Delta;
          ColorBand.Right := ColorBand.Left + Delta;
        end;
      end; {case}
      { Calculate the color band's color }
      Brush := CreateSolidBrush(RGB(
        StartRGB[0] + MulDiv(I, RGBDelta[0], Colors - 1),
        StartRGB[1] + MulDiv(I, RGBDelta[1], Colors - 1),
        StartRGB[2] + MulDiv(I, RGBDelta[2], Colors - 1)));
      FillRect(Canvas.Handle, ColorBand, Brush);
      DeleteObject(Brush);
    end;
  end;
  if Direction in [fdTopToBottom, fdBottomToTop] then
    Delta := HeightOf(ARect) mod Colors
  else Delta := WidthOf(ARect) mod Colors;
  if Delta > 0 then begin
    case Direction of
      { Calculate the color band's top and bottom coordinates }
      fdTopToBottom, fdBottomToTop: begin
        ColorBand.Top := ARect.Bottom - Delta;
        ColorBand.Bottom := ColorBand.Top + Delta;
      end;
      { Calculate the color band's left and right coordinates }
      fdLeftToRight, fdRightToLeft: begin
        ColorBand.Left := ARect.Right - Delta;
        ColorBand.Right := ColorBand.Left + Delta;
      end;
    end; {case}
    case Direction of
      fdTopToBottom, fdLeftToRight:
        Brush := CreateSolidBrush(EndColor);
      else {fdBottomToTop, fdRightToLeft }
        Brush := CreateSolidBrush(StartColor);
    end;
    FillRect(Canvas.Handle, ColorBand, Brush);
    DeleteObject(Brush);
  end;
end;


procedure GradientVertLine (Canvas : TCanvas; X, Y, Len : Integer; StartColor,
  EndColor: TColor; Direction: TFillDirection; Colors: Byte);
begin
  if Len < 1 then Exit;
end;



end.