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{
fpGUI - Free Pascal GUI Toolkit
Copyright (C) 2006 - 2012 See the file AUTHORS.txt, included in this
distribution, for details of the copyright.
See the file COPYING.modifiedLGPL, included in this distribution,
for details about redistributing fpGUI.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Description:
Defines two types of TrackBar controls. Also known as Slider controls.
}
unit fpg_trackbar;
{$mode objfpc}{$H+}
{
TODO:
- TfpgTrackBarExtra
* Tick line orientation (top, bottom, left or right)
* Slide the slider with the mouse button down (like a scrollbar)
* Slider button style (rectangle, pointer, double pointer)
* Tick captions
- TfpgTrackBar
* Vertical orientation
* show ticks property
}
interface
uses
Classes,
SysUtils,
fpg_base,
fpg_main,
fpg_widget;
type
TTrackBarChange = procedure(Sender: TObject; APosition: integer) of object;
TfpgBaseTrackBar = class(TfpgWidget)
private
FPosition: integer;
FMax: integer;
FMin: integer;
FOrientation: TOrientation;
FOnChange: TTrackBarChange;
procedure DoChange;
procedure SetTBPosition(AValue: integer);
procedure SetMax(const AValue: integer);
procedure SetMin(const AValue: integer);
protected
property Max: integer read FMax write SetMax default 100;
property Min: integer read FMin write SetMin default 0;
property Orientation: TOrientation read FOrientation write FOrientation default orHorizontal;
property Position: integer read FPosition write SetTBPosition default 0;
property OnChange: TTrackBarChange read FOnChange write FOnChange;
public
constructor Create(AOwner: TComponent); override;
end;
TfpgTrackBarExtra = class(TfpgBaseTrackBar)
private
FSliderSize: integer;
procedure SetSliderSize(const AValue: integer);
procedure FixMinMaxOrder;
procedure FixPositionLimits;
procedure DrawSlider(p: integer);
protected
procedure HandlePaint; override;
procedure HandleLMouseUp(x, y: integer; shiftstate: TShiftState); override;
procedure HandleKeyPress(var keycode: word; var shiftstate: TShiftState; var consumed: boolean); override;
public
constructor Create(AOwner: TComponent); override;
published
property Align;
property BackgroundColor;
property Hint;
property Max default 10;
property Min;
property Orientation;
property Position;
property ShowHint;
property SliderSize: integer read FSliderSize write SetSliderSize default 11;
property TabOrder;
property OnChange;
property OnShowHint;
end;
TfpgTrackBar = class(TfpgBaseTrackBar)
private
FScrollStep: integer;
FShowPosition: boolean;
FSliderPos: TfpgCoord;
FSliderLength: TfpgCoord;
FSliderDragging: boolean;
FSliderDragPos: TfpgCoord;
FSliderDragStart: TfpgCoord;
FMousePosition: TPoint;
FFont: TfpgFont;
procedure SetShowPosition(const AValue: boolean);
function GetTextWidth: TfpgCoord;
protected
procedure HandleLMouseDown(x, y: integer; shiftstate: TShiftState); override;
procedure HandleLMouseUp(x, y: integer; shiftstate: TShiftState); override;
procedure HandleMouseMove(x, y: integer; btnstate: word; shiftstate: TShiftState); override;
procedure HandlePaint; override;
procedure DrawSlider(recalc: boolean); virtual;
public
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
published
property Align;
property BackgroundColor;
property Enabled;
property Hint;
property Max;
property Min;
property Orientation;
property ParentShowHint;
property Position;
property ScrollStep: integer read FScrollStep write FScrollStep default 1;
property ShowHint;
property ShowPosition: boolean read FShowPosition write SetShowPosition default False;
property TabOrder;
property TextColor;
property OnChange;
property OnEnter;
property OnExit;
property OnShowHint;
end;
implementation
{ TfpgBaseTrackBar }
procedure TfpgBaseTrackBar.DoChange;
begin
if Assigned(FOnChange) then
FOnChange(self, FPosition);
end;
procedure TfpgBaseTrackBar.SetTBPosition(AValue: integer);
begin
if FPosition = AValue then
Exit; //==>
if AValue < FMin then
FPosition := FMin
else if AValue > FMax then
FPosition := FMax
else
FPosition := AValue;
RePaint;
DoChange;
end;
procedure TfpgBaseTrackBar.SetMax(const AValue: integer);
begin
if AValue = FMax then
Exit;
if AValue < FMin then
FMax := FMin
else
FMax := AValue;
if FPosition > FMax then
SetTBPosition(FMax);
Repaint;
end;
procedure TfpgBaseTrackBar.SetMin(const AValue: integer);
begin
if AValue = FMin then
Exit;
if AValue > FMax then
FMin := FMax
else
FMin := AValue;
if FPosition < FMin then
SetTBPosition(FMin);
Repaint;
end;
constructor TfpgBaseTrackBar.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FFocusable := True;
FMin := 0;
FMax := 100;
FPosition := 0;
FOrientation := orHorizontal;
FTextColor := Parent.TextColor;
FBackgroundColor := Parent.BackgroundColor;
FOnChange := nil;
end;
{ TfpgTrackBarExtra }
procedure TfpgTrackBarExtra.SetSliderSize(const AValue: integer);
begin
if FSliderSize = AValue then
Exit; //==>
if AValue > 11 then
begin
FSliderSize := AValue;
RePaint;
end;
end;
procedure TfpgTrackBarExtra.FixMinMaxOrder;
var
lmin: integer;
lmax: integer;
begin
if FMax < FMin then
begin
lmin := FMax; // change order
lmax := FMin;
FMax := lmax; // reassign values
FMin := lmin;
end;
end;
procedure TfpgTrackBarExtra.FixPositionLimits;
begin
if FPosition < FMin then
FPosition := FMin;
if FPosition > FMax then
FPosition := FMax;
end;
procedure TfpgTrackBarExtra.DrawSlider(p: integer);
var
h: integer;
begin
if Orientation = orHorizontal then
begin
h := Height div 2 - 1;
Canvas.SetColor(clHilite1);
Canvas.DrawLine(p - FSliderSize div 2,5, p + FSliderSize div 2, 5);
Canvas.DrawLine(p - FSliderSize div 2,5, p - FSliderSize div 2, h - FSliderSize div 2);
Canvas.DrawLine(p - FSliderSize div 2, h - FSliderSize div 2, p, h + FSliderSize div 2);
Canvas.SetColor(clHilite2);
Canvas.DrawLine(p - FSliderSize div 2 + 1,6, p + FSliderSize div 2 - 1, 6);
Canvas.DrawLine(p - FSliderSize div 2 + 1,6, p - FSliderSize div 2 + 1, h - FSliderSize div 2);
Canvas.DrawLine(p - FSliderSize div 2 + 1, h - FSliderSize div 2, p, h + FSliderSize div 2 - 1);
Canvas.SetColor(clShadow2);
Canvas.DrawLine(p + FSliderSize div 2, 6, p + FSliderSize div 2, h - FSliderSize div 2);
Canvas.DrawLine(p + FSliderSize div 2, h - FSliderSize div 2, p + 1, h + FSliderSize div 2 - 1);
Canvas.SetColor(clShadow1);
Canvas.DrawLine(p + FSliderSize div 2 - 1, 7, p + FSliderSize div 2 - 1, h - FSliderSize div 2);
Canvas.DrawLine(p + FSliderSize div 2 - 1, h - FSliderSize div 2, p + 1, h + FSliderSize div 2 - 2);
end
else
begin
h := Width div 2 - 1;
Canvas.SetColor(clHilite1);
Canvas.DrawLine(5,p - FSliderSize div 2, 5, p + FSliderSize div 2);
Canvas.DrawLine(5,p - FSliderSize div 2, h - FSliderSize div 2, p - FSliderSize div 2);
Canvas.DrawLine( h - FSliderSize div 2, p - FSliderSize div 2, h + FSliderSize div 2,p);
Canvas.SetColor(clHilite2);
Canvas.DrawLine(6,p - FSliderSize div 2 + 1, 6, p + FSliderSize div 2 - 1);
Canvas.DrawLine(6,p - FSliderSize div 2 + 1, h - FSliderSize div 2, p - FSliderSize div 2 + 1);
Canvas.DrawLine(h - FSliderSize div 2,p - FSliderSize div 2 + 1, h + FSliderSize div 2 - 1,p);
Canvas.SetColor(clShadow2);
Canvas.DrawLine( 6,p + FSliderSize div 2, h - FSliderSize div 2, p + FSliderSize div 2);
Canvas.DrawLine( h - FSliderSize div 2,p + FSliderSize div 2, h + FSliderSize div 2 - 1, p + 1);
Canvas.SetColor(clShadow1);
Canvas.DrawLine( 7, p + FSliderSize div 2 - 1, h - FSliderSize div 2,p + FSliderSize div 2 - 1);
Canvas.DrawLine( h - FSliderSize div 2, p + FSliderSize div 2 - 1, h + FSliderSize div 2 - 2, p + 1);
end;
end;
procedure TfpgTrackBarExtra.HandlePaint;
var
r: TfpgRect;
linepos: double;
drawwidth: integer;
i: integer;
begin
// inherited HandlePaint;
r.SetRect(0, 0, Width, Height);
Canvas.Clear(FBackgroundColor);
if FFocused then
Canvas.SetColor(clWidgetFrame)
else
Canvas.SetColor(clInactiveWgFrame);
Canvas.DrawRectangle(r);
FixMinMaxOrder;
FixPositionLimits;
if Orientation = orHorizontal then
begin
drawwidth := Width - 5 - FSliderSize;
linepos := FMax - FMin;
if linepos <> 0 then
begin
linepos := drawwidth / linepos;
Canvas.SetColor(clWidgetFrame);
for i := 0 to (FMax - FMin) do
Canvas.DrawLine(round(2 + (FSliderSize div 2) + (linepos * i)), Height div 2 + FSliderSize * 2, round(2 + FSliderSize div 2 + linepos * i), Height - 5);
DrawSlider(round(2 + FSliderSize div 2 + linepos * position));
end;
end
else
begin
drawwidth := Height - 5 - FSliderSize;
linepos := FMax - FMin;
if linepos <> 0 then
begin
linepos := drawwidth / linepos;
Canvas.SetColor(clWidgetFrame);
for i := 0 to (FMax - FMin) do
Canvas.DrawLine(Width div 2 + FSliderSize * 2, round(2 + (FSliderSize div 2) + (linepos * i)), Width - 5, round(2 + FSliderSize div 2 + linepos * i));
DrawSlider(round(2 + FSliderSize div 2 + linepos * position));
end;
end; { if/else }
end;
procedure TfpgTrackBarExtra.HandleLMouseUp(x, y: integer; shiftstate: TShiftState);
var
linepos: double;
drawwidth: integer;
OldPos: integer;
begin
OldPos := Position;
FixMinMaxOrder;
linepos := FMax - FMin;
if Orientation = orHorizontal then
begin
drawwidth := Width - 5 - FSliderSize;
linepos := drawwidth / linepos;
FPosition := round((x - 2 - FSliderSize div 2) / linepos) + FMin;
end
else
begin
drawwidth := Height - 5 - FSliderSize;
linepos := drawwidth / linepos;
FPosition := round((y - 2 - FSliderSize div 2) / linepos) + FMin;
end;
RePaint;
if Position <> OldPos then
DoChange;
// inherited HandleLMouseUp(x, y, shiftstate);
end;
procedure TfpgTrackBarExtra.HandleKeyPress(var keycode: word;
var shiftstate: TShiftState; var consumed: boolean);
var
OldPos: integer;
begin
consumed := True;
OldPos := FPosition;
if Orientation = orHorizontal then
begin
case keycode of
keyLeft: Position := Position - 1;
keyRight: Position := Position + 1;
keyPageUp: Position := FMin;
keyPageDown: Position := FMax;
else
consumed := False;
end;
end
else
begin
case keycode of
keyUp: Position := Position - 1;
keyDown: Position := Position + 1;
keyPageUp: Position := FMin;
keyPageDown: Position := FMax;
else
consumed := False;
end;
end; { if/else }
inherited HandleKeyPress(keycode, shiftstate, consumed);
if OldPos <> Position then
DoChange;
end;
constructor TfpgTrackBarExtra.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FMax := 10;
FSliderSize := 11;
end;
{ TfpgTrackBar }
procedure TfpgTrackBar.SetShowPosition(const AValue: boolean);
begin
if FShowPosition = AValue then
Exit; //==>
FShowPosition := AValue;
RePaint;
end;
function TfpgTrackBar.GetTextWidth: TfpgCoord;
begin
if FShowPosition then
Result := FFont.TextWidth(IntToStr(Max)) + 4
else
Result := 0;
end;
procedure TfpgTrackBar.HandleLMouseDown(x, y: integer; shiftstate: TShiftState);
var
tw: TfpgCoord;
begin
inherited HandleLMouseDown(x, y, shiftstate);
if Orientation = orVertical then
begin
if (y >= Width + FSliderPos) and (y <= Width + FSliderPos + FSliderLength) then
begin
FSliderDragging := True;
FSliderDragPos := y;
end;
end
else
begin
tw := GetTextWidth;
if (x >= FSliderPos) and (x <= (FSliderPos + FSliderLength + tw)) then
begin
FSliderDragging := True;
FSliderDragPos := x;
end;
end;
if FSliderDragging then
begin
FSliderDragStart := FSliderPos;
RePaint;
end;
end;
procedure TfpgTrackBar.HandleLMouseUp(x, y: integer; shiftstate: TShiftState);
begin
inherited HandleLMouseUp(x, y, shiftstate);
FSliderDragging := False;
RePaint;
end;
procedure TfpgTrackBar.HandleMouseMove(x, y: integer; btnstate: word; shiftstate: TShiftState);
var
d: integer;
area: integer;
newp: integer;
ppos: integer;
tw: TfpgCoord;
begin
inherited HandleMouseMove(x, y, btnstate, shiftstate);
FMousePosition.X := x;
FMousePosition.Y := y;
if (not FSliderDragging) or ((btnstate and MOUSE_LEFT) = 0) then
begin
FSliderDragging := False;
Exit;
end;
if Orientation = orVertical then
begin
d := y - FSliderDragPos;
area := Height - FSliderLength-4;
end
else
begin
d := x - FSliderDragPos;
tw := GetTextWidth;
area := Width - FSliderLength-4-tw;
end;
ppos := FSliderPos;
FSliderPos := FSliderDragStart + d;
if FSliderPos < 0 then
FSliderPos := 0;
if FSliderPos > area then
FSliderPos := area;
if area <> FMin then
newp := FMin + Trunc((FMax - FMin) * (FSliderPos / area))
else
newp := FMin;
if newp <> FPosition then
begin
Position := newp;
RePaint;
DoChange;
end;
end;
procedure TfpgTrackBar.HandlePaint;
var
r: TfpgRect;
begin
DrawSlider(True);
{ dont't draw focus rect while dragging - it flickers }
if Focused and (not FSliderDragging) then
begin
r.SetRect(0, 0, Width, Height);
Canvas.DrawFocusRect(r);
end;
end;
procedure TfpgTrackBar.DrawSlider(recalc: boolean);
var
area: TfpgCoord;
mm: TfpgCoord;
r: TfpgRect;
tw: TfpgCoord;
begin
Canvas.Clear(FBackgroundColor);
Canvas.SetColor(FBackgroundColor);
if Orientation = orVertical then
area := Height-4
else
begin
tw := GetTextWidth;
area := Width-4-tw;
end;
if recalc then
begin
if FPosition > FMax then
FPosition := FMax;
if FPosition < FMin then
FPosition := FMin;
mm := FMax - FMin;
area := area - FSliderLength;
if mm = 0 then
FSliderPos := FMin
else
FSliderPos := Trunc(area * ((FPosition - FMin) / mm));
if FPosition = FMin then
inc(FSliderPos, 2);
end;
if Orientation = orVertical then
begin
Canvas.DrawButtonFace(0, Width + FSliderPos, Width, FSliderLength, [btfIsEmbedded]);
end
else
begin
r.SetRect(1, (Height-4) div 2, Width - tw - 4, 4);
Canvas.DrawControlFrame(r);
r.SetRect(FSliderPos, (Height-20) div 2, FSliderLength, 21);
Canvas.DrawButtonFace(r, []);
if FShowPosition then
begin
Canvas.SetTextColor(TextColor);
fpgStyle.DrawString(Canvas, Width - tw, (Height - FFont.Height) div 2, IntToStr(Position), Enabled);
end;
end;
end;
constructor TfpgTrackBar.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
Height := 30;
Width := 100;
FSliderPos := 0;
FSliderDragging := False;
FSliderLength := 11;
FScrollStep := 1;
FShowPosition := False;
FFont := fpgGetFont('#Grid');
end;
destructor TfpgTrackBar.Destroy;
begin
FFont.Free;
inherited Destroy;
end;
end.
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