Double Gradient

Unit

Whit this unit 'doublegradient' you can easy make gradients for toolbars, buttons, etc. Save the above code in a text file 'doublegradient.pas' and add in the 'uses' section of your project.

<delphi>unit doublegradient;

{$mode objfpc}{$H+}

interface

uses

 Classes, Graphics;

function DoubleGradientFill(ARect: TRect; AStart1,AStop1,AStart2,AStop2: TColor;

 ADirection1,ADirection2,APos: TGradientDirection; AValue: Single): TBitmap;

implementation

function DoubleGradientFill(ARect: TRect; AStart1,AStop1,AStart2,AStop2: TColor;

 ADirection1,ADirection2,APos: TGradientDirection; AValue: Single): TBitmap;

var

 ABitmap: TBitmap; ARect1,ARect2: TRect;

begin

 ABitmap := TBitmap.Create;
 ABitmap.Width:=ARect.Right;
 ABitmap.Height:=ARect.Bottom;
 if AValue <> 0 then begin
   ARect1:=ARect;
 end;
 if AValue <> 1 then begin
   ARect2:=ARect;
 end;
 if APos = gdVertical then begin
   ARect1.Bottom:=Round(ARect1.Bottom * AValue);
   ARect2.Top:=ARect1.Bottom;
 end
 else if APos = gdHorizontal then begin
   ARect1.Right:=Round(ARect1.Right * AValue);
   ARect2.Left:=ARect1.Right;
 end;
 if AValue <> 0 then begin
   ABitmap.Canvas.GradientFill(ARect1,AStart1,AStop1,ADirection1);
 end;
 if AValue <> 1 then begin
   ABitmap.Canvas.GradientFill(ARect2,AStart2,AStop2,ADirection2);
 end;
 Result:=ABitmap;

end;

end.</delphi>

Usage

First you must have a 'TBitmap' to store the gradient, then you can draw the image, for example, in all the form visible area:

<delphi>procedure TForm1.FormPaint(Sender: TObject); var

 ABitmap: TBitmap;

begin

 ABitmap:=DoubleGradientFill(ClientRect,clMedGray,clWhite,clSilver,clGray,gdVertical,gdVertical,gdVertical,0.50);
 Self.Canvas.Draw(0,0,ABitmap);
 ABitmap.Free

end;</delphi>

The result bitmap:

Editor

Also you can use the 'Double Gradient Editor' that is a GUI to instant see the result, save to a bitmap file, save to '*.doublegradient' session file or just copy code to clipboard to use in lazarus.

• To acces the menu right click the ScrollBox:
  • Save bitmap.. Show a dialog to save as a *.bmp file.
  • Load gradient.. Show a dialog to load a *.doublegradient session file.
  • Save gradient.. Show a dialog to save the current session settings to a file.
  • Copy code to clipboard.. Just copy the settings as text in the clipboard, then you can use it to paste in lazarus source editor to call the doublegradientfill procedure.

• default.doublegradient: this file have the last settings in the editor, is loaded at startup, saved when you close the application.

Download

Double Gradient Editor 1.0 [1]

You are free to edit and improve this editor, solve the bugs..