lazarus/components/tachart/talegend.pas
2011-03-23 07:14:16 +00:00

563 lines
15 KiB
ObjectPascal

{
*****************************************************************************
* *
* See the file COPYING.modifiedLGPL.txt, included in this distribution, *
* for details about the copyright. *
* *
* 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. *
* *
*****************************************************************************
Authors: Alexander Klenin
}
unit TALegend;
{$H+}
interface
uses
Classes, Contnrs, FPCanvas, Graphics, SysUtils,
TAChartUtils, TADrawUtils, TATypes;
const
DEF_LEGEND_SPACING = 4;
DEF_LEGEND_MARGIN = 4;
DEF_LEGEND_SYMBOL_WIDTH = 20;
type
{ TLegendItem }
TLegendItem = class
private
FColor: TColor;
FText: String;
public
constructor Create(const AText: String; AColor: TColor = clTAColor);
procedure Draw(ADrawer: IChartDrawer; const ARect: TRect); virtual;
public
property Color: TColor read FColor write FColor;
end;
TLegendItemDrawEvent = procedure (
ACanvas: TCanvas; const ARect: TRect; AIndex: Integer; var AText: String
) of object;
{ TLegendItemUserDrawn }
TLegendItemUserDrawn = class(TLegendItem)
private
FIndex: Integer;
FOnDraw: TLegendItemDrawEvent;
public
constructor Create(
AIndex: Integer; AOnDraw: TLegendItemDrawEvent; const AText: String);
procedure Draw(ADrawer: IChartDrawer; const ARect: TRect); override;
property OnDraw: TLegendItemDrawEvent read FOnDraw;
end;
{ TLegendItemLine }
TLegendItemLine = class(TLegendItem)
private
FPen: TFPCustomPen;
public
constructor Create(APen: TFPCustomPen; const AText: String);
procedure Draw(ADrawer: IChartDrawer; const ARect: TRect); override;
end;
{ TLegendItemLinePointer }
TLegendItemLinePointer = class(TLegendItemLine)
protected
FPointer: TSeriesPointer;
public
constructor Create(
APen: TPen; APointer: TSeriesPointer; const AText: String);
procedure Draw(ADrawer: IChartDrawer; const ARect: TRect); override;
end;
{ TLegendItemBrushRect }
TLegendItemBrushRect = class(TLegendItem)
private
FBrush: TFPCustomBrush;
public
constructor Create(ABrush: TFPCustomBrush; const AText: String);
procedure Draw(ADrawer: IChartDrawer; const ARect: TRect); override;
end;
{ TLegendItemPieSlice }
TLegendItemPieSlice = class(TLegendItem)
public
procedure Draw(ADrawer: IChartDrawer; const ARect: TRect); override;
end;
TChartLegendItems = TObjectList;
TChartLegendBrush = class(TBrush)
published
property Color default clWhite;
end;
TLegendAlignment = (
laTopLeft, laCenterLeft, laBottomLeft,
laTopCenter, laBottomCenter, // laCenterCenter makes no sense.
laTopRight, laCenterRight, laBottomRight);
{ TChartLegend }
TChartLegend = class(TChartElement)
private
FAlignment: TLegendAlignment;
FBackgroundBrush: TChartLegendBrush;
FFont: TFont;
FFrame: TChartPen;
FMarginX: TChartDistance;
FMarginY: TChartDistance;
FSpacing: TChartDistance;
FSymbolWidth: TChartDistance;
FUseSidebar: Boolean;
procedure SetAlignment(AValue: TLegendAlignment);
procedure SetBackgroundBrush(AValue: TChartLegendBrush);
procedure SetFont(AValue: TFont);
procedure SetFrame(AValue: TChartPen);
procedure SetMargin(AValue: TChartDistance);
procedure SetMarginX(AValue: TChartDistance);
procedure SetMarginY(AValue: TChartDistance);
procedure SetSpacing(AValue: TChartDistance);
procedure SetSymbolWidth(AValue: TChartDistance);
procedure SetUseSidebar(AValue: Boolean);
public
constructor Create(AOwner: TCustomChart);
destructor Destroy; override;
public
procedure Assign(Source: TPersistent); override;
procedure Draw(
ADrawer: IChartDrawer; AItems: TObjectList; const ABounds: TRect);
function Prepare(
ADrawer: IChartDrawer; AItems: TObjectList; var AClipRect: TRect): TRect;
published
property Alignment: TLegendAlignment
read FAlignment write SetAlignment default laTopRight;
property BackgroundBrush: TChartLegendBrush
read FBackgroundBrush write SetBackgroundBrush;
property Font: TFont read FFont write SetFont;
property Frame: TChartPen read FFrame write SetFrame;
property Margin: TChartDistance
read FMarginX write SetMargin stored false; deprecated;
property MarginX: TChartDistance
read FMarginX write SetMarginX default DEF_LEGEND_MARGIN;
property MarginY: TChartDistance
read FMarginY write SetMarginY default DEF_LEGEND_MARGIN;
property Spacing: TChartDistance
read FSpacing write SetSpacing default DEF_LEGEND_SPACING;
property SymbolWidth: TChartDistance
read FSymbolWidth write SetSymbolWidth default DEF_LEGEND_SYMBOL_WIDTH;
property UseSidebar: Boolean read FUseSidebar write SetUseSidebar default true;
property Visible default false;
end;
TLegendMultiplicity = (lmSingle, lmPoint);
{ TChartSeriesLegend }
TChartSeriesLegend = class(TChartElement)
private
FMultiplicity: TLegendMultiplicity;
FOnDraw: TLegendItemDrawEvent;
FUserItemsCount: Integer;
procedure SetMultiplicity(AValue: TLegendMultiplicity);
procedure SetOnDraw(AValue: TLegendItemDrawEvent);
procedure SetUserItemsCount(AValue: Integer);
public
constructor Create(AOwner: TCustomChart);
public
procedure Assign(Source: TPersistent); override;
published
property Multiplicity: TLegendMultiplicity
read FMultiplicity write SetMultiplicity default lmSingle;
property OnDraw: TLegendItemDrawEvent read FOnDraw write SetOnDraw;
property UserItemsCount: Integer
read FUserItemsCount write SetUserItemsCount default 1;
property Visible default true;
end;
implementation
uses
Math, PropEdits, Types, TADrawerCanvas;
const
SYMBOL_TEXT_SPACING = 4;
{ TLegendItem }
constructor TLegendItem.Create(const AText: String; AColor: TColor);
begin
FColor := AColor;
FText := AText;
end;
procedure TLegendItem.Draw(ADrawer: IChartDrawer; const ARect: TRect);
begin
ADrawer.TextOut.
Pos(ARect.Right + SYMBOL_TEXT_SPACING, ARect.Top).Text(FText).Done;
end;
{ TLegendItemUserDrawn }
constructor TLegendItemUserDrawn.Create(
AIndex: Integer; AOnDraw: TLegendItemDrawEvent; const AText: String);
begin
inherited Create(AText);
FIndex := AIndex;
FOnDraw := AOnDraw;
end;
procedure TLegendItemUserDrawn.Draw(ADrawer: IChartDrawer; const ARect: TRect);
var
ic: IChartTCanvasDrawer;
begin
if Supports(ADrawer, IChartTCanvasDrawer, ic) and Assigned(FOnDraw) then
FOnDraw(ic.Canvas, ARect, FIndex, FText);
inherited Draw(ADrawer, ARect);
end;
{ TLegendItemLine }
constructor TLegendItemLine.Create(APen: TFPCustomPen; const AText: String);
begin
inherited Create(AText);
FPen := APen;
end;
procedure TLegendItemLine.Draw(ADrawer: IChartDrawer; const ARect: TRect);
var
y: Integer;
begin
inherited Draw(ADrawer, ARect);
if FPen = nil then exit;
ADrawer.Pen := FPen;
y := (ARect.Top + ARect.Bottom) div 2;
ADrawer.Line(ARect.Left, y, ARect.Right, y);
end;
{ TLegendItemLinePointer }
constructor TLegendItemLinePointer.Create(
APen: TPen; APointer: TSeriesPointer; const AText: String);
begin
inherited Create(APen, AText);
FPointer := APointer;
end;
procedure TLegendItemLinePointer.Draw(
ADrawer: IChartDrawer; const ARect: TRect);
var
c, sz: TPoint;
begin
inherited Draw(ADrawer, ARect);
if FPointer = nil then exit;
c := CenterPoint(ARect);
// Max width slightly narrower then ARect to leave place for the line.
sz.X := Min(FPointer.HorizSize, (ARect.Right - ARect.Left) div 3);
sz.Y := Min(FPointer.VertSize, (ARect.Bottom - ARect.Top) div 2);
FPointer.DrawSize(ADrawer, c, sz, Color);
end;
{ TLegendItemBrushRect }
constructor TLegendItemBrushRect.Create(
ABrush: TFPCustomBrush; const AText: String);
begin
inherited Create(AText);
FBrush := ABrush;
end;
procedure TLegendItemBrushRect.Draw(ADrawer: IChartDrawer; const ARect: TRect);
begin
inherited Draw(ADrawer, ARect);
if FBrush = nil then
ADrawer.SetBrushParams(bsSolid, IfThen(Color = clTAColor, clRed, Color))
else begin
ADrawer.Brush := FBrush;
if Color <> clTAColor then
ADrawer.SetBrushParams(FBrush.Style, Color);
end;
ADrawer.Rectangle(ARect);
end;
{ TLegendItemPieSlice }
procedure TLegendItemPieSlice.Draw(ADrawer: IChartDrawer; const ARect: TRect);
const
ANGLE = 30 * 16;
var
bc: TChartColor = clRed;
begin
inherited Draw(ADrawer, ARect);
if Color <> clTAColor then
bc := Color;
ADrawer.SetBrushParams(bsSolid, bc);
ADrawer.RadialPie(
2 * ARect.Left - ARect.Right, ARect.Top, ARect.Right, ARect.Bottom,
-ANGLE, 2 * ANGLE);
end;
{ TChartLegend }
procedure TChartLegend.Assign(Source: TPersistent);
begin
if Source is TChartLegend then
with TChartLegend(Source) do
Self.FAlignment := FAlignment;
inherited Assign(Source);
end;
constructor TChartLegend.Create(AOwner: TCustomChart);
begin
inherited Create(AOwner);
FAlignment := laTopRight;
FMarginX := DEF_LEGEND_MARGIN;
FMarginY := DEF_LEGEND_MARGIN;
FSpacing := DEF_LEGEND_SPACING;
FSymbolWidth := DEF_LEGEND_SYMBOL_WIDTH;
FUseSidebar := true;
Visible := false;
InitHelper(FBackgroundBrush, TChartLegendBrush);
InitHelper(FFont, TFont);
InitHelper(FFrame, TChartPen);
end;
destructor TChartLegend.Destroy;
begin
FreeAndNil(FBackgroundBrush);
FreeAndNil(FFont);
FreeAndNil(FFrame);
inherited;
end;
procedure TChartLegend.Draw(
ADrawer: IChartDrawer; AItems: TObjectList; const ABounds: TRect);
var
i, itemHeight: Integer;
r: TRect;
begin
// Draw the background and the border.
ADrawer.Font := Font;
ADrawer.Brush := BackgroundBrush;
ADrawer.Pen := Frame;
ADrawer.Rectangle(ABounds);
if AItems.Count = 0 then exit;
try
r := ABounds;
r.Right -= 1;
ADrawer.ClippingStart(r);
itemHeight :=
(ABounds.Bottom - ABounds.Top - Spacing) div AItems.Count - Spacing;
r := Bounds(
ABounds.Left + Spacing, ABounds.Top + Spacing, SymbolWidth, itemHeight);
for i := 0 to AItems.Count - 1 do begin
ADrawer.Font := Font;
ADrawer.Brush := BackgroundBrush;
ADrawer.Pen := Frame;
(AItems[i] as TLegendItem).Draw(ADrawer, r);
OffsetRect(r, 0, itemHeight + Spacing);
end;
finally
ADrawer.ClippingStop;
end;
end;
function TChartLegend.Prepare(
ADrawer: IChartDrawer; AItems: TObjectList; var AClipRect: TRect): TRect;
var
x, y, i, textHeight: Integer;
sidebar, legendSize: TPoint;
begin
ADrawer.Font := Font;
// Measure the legend.
legendSize.X := 0;
textHeight := 0;
for i := 0 to AItems.Count - 1 do
with ADrawer.TextExtent((AItems[i] as TLegendItem).FText) do begin
legendSize.X := Max(X, legendSize.X);
textHeight := Max(Y, textHeight);
end;
legendSize.X += 2 * Spacing + SYMBOL_TEXT_SPACING + SymbolWidth;
sidebar.X := 2 * MarginX;
with AClipRect do
legendSize.X := EnsureRange(legendSize.X, 0, Right - Left - sidebar.X);
sidebar.X += legendSize.X;
legendSize.Y := Spacing + AItems.Count * (textHeight + Spacing);
sidebar.Y := 2 * MarginX;
with AClipRect do
legendSize.Y := EnsureRange(legendSize.Y, 0, Bottom - Top - sidebar.Y);
sidebar.Y += legendSize.Y;
// Determine position according to the alignment.
case Alignment of
laTopLeft, laCenterLeft, laBottomLeft:
x := AClipRect.Left + MarginX;
laTopRight, laCenterRight, laBottomRight:
x := AClipRect.Right - legendSize.X - MarginX;
laTopCenter, laBottomCenter:
x := (AClipRect.Right + AClipRect.Left - legendSize.X) div 2;
end;
case Alignment of
laTopLeft, laTopCenter, laTopRight:
y := AClipRect.Top + MarginY;
laBottomLeft, laBottomCenter, laBottomRight:
y := AClipRect.Bottom - MarginY - legendSize.Y;
laCenterLeft, laCenterRight:
y := (AClipRect.Top + AClipRect.Bottom - legendSize.Y) div 2;
end;
if UseSidebar then
case Alignment of
laTopLeft, laCenterLeft, laBottomLeft:
AClipRect.Left += sidebar.X;
laTopRight, laCenterRight, laBottomRight:
AClipRect.Right -= sidebar.X;
laTopCenter:
AClipRect.Top += legendSize.Y + 2 * MarginY;
laBottomCenter:
AClipRect.Bottom -= legendSize.Y + 2 * MarginY;
end;
Result := Bounds(x, y, legendSize.X, legendSize.Y);
end;
procedure TChartLegend.SetAlignment(AValue: TLegendAlignment);
begin
if FAlignment = AValue then exit;
FAlignment := AValue;
StyleChanged(Self);
end;
procedure TChartLegend.SetBackgroundBrush(AValue: TChartLegendBrush);
begin
FBackgroundBrush.Assign(AValue);
StyleChanged(Self);
end;
procedure TChartLegend.SetFont(AValue: TFont);
begin
FFont.Assign(AValue);
StyleChanged(Self);
end;
procedure TChartLegend.SetFrame(AValue: TChartPen);
begin
FFrame.Assign(AValue);
StyleChanged(Self);
end;
procedure TChartLegend.SetMargin(AValue: TChartDistance);
begin
SetMarginX(AValue);
SetMarginY(AValue);
end;
procedure TChartLegend.SetMarginX(AValue: TChartDistance);
begin
if FMarginX = AValue then exit;
FMarginX := AValue;
StyleChanged(Self);
end;
procedure TChartLegend.SetMarginY(AValue: TChartDistance);
begin
if FMarginY = AValue then exit;
FMarginY := AValue;
StyleChanged(Self);
end;
procedure TChartLegend.SetSpacing(AValue: TChartDistance);
begin
if FSpacing = AValue then exit;
FSpacing := AValue;
StyleChanged(Self);
end;
procedure TChartLegend.SetSymbolWidth(AValue: TChartDistance);
begin
if FSymbolWidth = AValue then exit;
FSymbolWidth := AValue;
StyleChanged(Self);
end;
procedure TChartLegend.SetUseSidebar(AValue: Boolean);
begin
if FUseSidebar = AValue then exit;
FUseSidebar := AValue;
StyleChanged(Self);
end;
{ TChartSeriesLegend }
procedure TChartSeriesLegend.Assign(Source: TPersistent);
begin
if Source is TChartSeriesLegend then
with TChartSeriesLegend(Source) do begin
Self.FMultiplicity := FMultiplicity;
Self.FOnDraw := FOnDraw;
Self.FUserItemsCount := FUserItemsCount;
end;
inherited Assign(Source);
end;
constructor TChartSeriesLegend.Create(AOwner: TCustomChart);
begin
inherited Create(AOwner);
FVisible := true;
FUserItemsCount := 1;
end;
procedure TChartSeriesLegend.SetMultiplicity(AValue: TLegendMultiplicity);
begin
if FMultiplicity = AValue then exit;
FMultiplicity := AValue;
StyleChanged(Self);
end;
procedure TChartSeriesLegend.SetOnDraw(AValue: TLegendItemDrawEvent);
begin
if TMethod(FOnDraw) = TMethod(AValue) then exit;
FOnDraw := AValue;
StyleChanged(Self);
end;
procedure TChartSeriesLegend.SetUserItemsCount(AValue: Integer);
begin
if FUserItemsCount = AValue then exit;
FUserItemsCount := AValue;
StyleChanged(Self);
end;
procedure SkipObsoleteProperties;
begin
RegisterPropertyEditor(
TypeInfo(TChartDistance), TChartLegend, 'Margin', THiddenPropertyEditor);
end;
initialization
SkipObsoleteProperties;
end.