From 8cc81d308aa68dffc0e9a89eb836167f07667192 Mon Sep 17 00:00:00 2001
From: ask <ask@lazarus-ide.org>
Date: Thu, 1 Apr 2010 12:59:11 +0000
Subject: [PATCH] TAChart: Make LogicalExtent settable property as a more
 general replacement for Pan method

git-svn-id: trunk@24350 -
---
 components/tachart/tagraph.pas | 28 +++++++++++-----------------
 components/tachart/tatools.pas | 12 ++++++++++--
 2 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/components/tachart/tagraph.pas b/components/tachart/tagraph.pas
index 1976f477c5..27d98b3c6d 100644
--- a/components/tachart/tagraph.pas
+++ b/components/tachart/tagraph.pas
@@ -147,6 +147,7 @@ type
     FFrame: TChartPen;
     FGraphBrush: TBrush;
     FLegend: TChartLegend;
+    FLogicalExtent: TDoubleRect;
     FMargins: TChartMargins;
     FOnDrawReticule: TDrawReticuleEvent;
     FSeries: TChartSeriesList;
@@ -159,7 +160,6 @@ type
     FClipRect: TRect;
     FCurrentExtent: TDoubleRect;
     FIsZoomed: Boolean;
-    FLogicalExtent: TDoubleRect;
     FOffset: TDoublePoint;   // Coordinates transformation
     FReticuleMode: TReticuleMode;
     FReticulePos: TPoint;
@@ -185,6 +185,7 @@ type
     procedure SetFrame(Value: TChartPen);
     procedure SetGraphBrush(Value: TBrush);
     procedure SetLegend(Value: TChartLegend);
+    procedure SetLogicalExtent(const AValue: TDoubleRect);
     procedure SetMargins(AValue: TChartMargins);
     procedure SetReticuleMode(const AValue: TReticuleMode);
     procedure SetReticulePos(const AValue: TPoint);
@@ -228,7 +229,6 @@ type
     procedure CopyToClipboardBitmap;
     procedure DeleteSeries(ASeries: TBasicChartSeries);
     procedure PaintOnCanvas(ACanvas: TCanvas; ARect: TRect);
-    procedure Pan(const ADelta: TPoint);
     procedure SaveToBitmapFile(const AFileName: String); inline;
     procedure SaveToFile(AClass: TRasterImageClass; const AFileName: String);
     function SaveToImage(AClass: TRasterImageClass): TRasterImage;
@@ -249,6 +249,7 @@ type
     property ChartWidth: Integer read GetChartWidth;
     property ClipRect: TRect read FClipRect;
     property CurrentExtent: TDoubleRect read FCurrentExtent;
+    property LogicalExtent: TDoubleRect read FLogicalExtent write SetLogicalExtent;
     property ReticulePos: TPoint read FReticulePos write SetReticulePos;
     property SeriesCount: Integer read GetSeriesCount;
     property XGraphMax: Double read FCurrentExtent.b.X;
@@ -481,21 +482,6 @@ begin
     Series[i].AfterDraw;
 end;
 
-procedure TChart.Pan(const ADelta: TPoint);
-var
-  d: TDoublePoint;
-begin
-  d.X := -ADelta.X / FScale.X;
-  d.Y := -ADelta.Y / FScale.Y;
-  with FLogicalExtent do begin
-    a += d;
-    b += d;
-  end;
-  FIsZoomed := true;
-  FCurrentExtent := FLogicalExtent;
-  Invalidate;
-end;
-
 procedure TChart.PrepareLegend(
   ACanvas: TCanvas; out ALegendItems: TChartLegendItems; out ARect: TRect);
 var
@@ -914,6 +900,14 @@ begin
   Invalidate;
 end;
 
+procedure TChart.SetLogicalExtent(const AValue: TDoubleRect);
+begin
+  FLogicalExtent := AValue;
+  FIsZoomed := true;
+  FCurrentExtent := FLogicalExtent;
+  Invalidate;
+end;
+
 procedure TChart.SetMargins(AValue: TChartMargins);
 begin
   FMargins.Assign(AValue);
diff --git a/components/tachart/tatools.pas b/components/tachart/tatools.pas
index b65d6c2a22..8bdbd86dc5 100644
--- a/components/tachart/tatools.pas
+++ b/components/tachart/tatools.pas
@@ -610,14 +610,22 @@ end;
 procedure TPanDragTool.MouseMove(APoint: TPoint);
 var
   d: TPoint;
+  dd: TDoublePoint;
+  ext: TDoubleRect;
 begin
   d := APoint - FOrigin;
+  FOrigin := APoint;
+
   if not (pdLeft in Directions) then d.X := Max(d.X, 0);
   if not (pdRight in Directions) then d.X := Min(d.X, 0);
   if not (pdUp in Directions) then d.Y := Max(d.Y, 0);
   if not (pdDown in Directions) then d.Y := Min(d.Y, 0);
-  FChart.Pan(d);
-  FOrigin := APoint;
+
+  dd := FChart.ImageToGraph(d) -  FChart.ImageToGraph(Point(0, 0));
+  ext := FChart.LogicalExtent;
+  ext.a += dd;
+  ext.b += dd;
+  FChart.LogicalExtent := ext;
 end;
 
 procedure TPanDragTool.MouseUp(APoint: TPoint);