From 325d098358c8ed32eedfdf75f21d5e6dfd09b8f7 Mon Sep 17 00:00:00 2001
From: ask <ask@lazarus-ide.org>
Date: Sat, 31 Jul 2010 16:55:24 +0000
Subject: [PATCH] TAChart: Fix zooming on auto-scaled series

git-svn-id: trunk@26940 -
---
 components/tachart/tagraph.pas           |  5 +++
 components/tachart/tatransformations.pas | 45 ++++++++++++++++--------
 2 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/components/tachart/tagraph.pas b/components/tachart/tagraph.pas
index acd0475bba..5dd32b8909 100644
--- a/components/tachart/tagraph.pas
+++ b/components/tachart/tagraph.pas
@@ -1046,6 +1046,11 @@ var
 begin
   Extent.CheckBoundsOrder;
 
+  for i := 0 to AxisList.Count - 1 do
+    with AxisList[i] do
+      if Transformations <> nil then
+        Transformations.ClearBounds;
+
   FLogicalExtent := EmptyExtent;
   for i := 0 to SeriesCount - 1 do begin
     s := Series[i];
diff --git a/components/tachart/tatransformations.pas b/components/tachart/tatransformations.pas
index 6f90743418..4623ce63e8 100644
--- a/components/tachart/tatransformations.pas
+++ b/components/tachart/tatransformations.pas
@@ -47,8 +47,9 @@ type
     procedure SetIndex(AValue: Integer); override;
   protected
     FDrawData: TDrawDataItem;
+    procedure ClearBounds; virtual;
     function GetDrawDataClass: TDrawDataItemClass; virtual;
-    procedure SetChart(AChart: TObject); virtual;
+    procedure SetChart(AChart: TObject);
     procedure UpdateBounds(var AMin, AMax: Double); virtual;
   public
     constructor Create(AOwner: TComponent); override;
@@ -86,6 +87,7 @@ type
     procedure SetChildOrder(Child: TComponent; Order: Integer); override;
   public
     function AxisToGraph(AX: Double): Double;
+    procedure ClearBounds;
     function GraphToAxis(AX: Double): Double;
     procedure SetChart(AChart: TObject);
     procedure UpdateBounds(var AMin, AMax: Double);
@@ -128,8 +130,8 @@ type
     procedure SetMaxValue(const AValue: Double);
     procedure SetMinValue(const AValue: Double);
   protected
+    procedure ClearBounds; override;
     function GetDrawDataClass: TDrawDataItemClass; override;
-    procedure SetChart(AChart: TObject); override;
     procedure UpdateBounds(var AMin, AMax: Double); override;
   public
     constructor Create(AOwner: TComponent); override;
@@ -326,6 +328,11 @@ begin
     Transformations.Broadcaster.Broadcast(Self);
 end;
 
+procedure TAxisTransform.ClearBounds;
+begin
+  // empty
+end;
+
 constructor TAxisTransform.Create(AOwner: TComponent);
 begin
   FEnabled := true;
@@ -433,6 +440,16 @@ begin
         Result := AxisToGraph(Result);
 end;
 
+procedure TChartAxisTransformations.ClearBounds;
+var
+  i: Integer;
+begin
+  for i := List.Count - 1 downto 0 do
+    with TAxisTransform(List[i]) do
+      if Enabled then
+        ClearBounds;
+end;
+
 constructor TChartAxisTransformations.Create(AOwner: TComponent);
 begin
   inherited Create(AOwner);
@@ -610,6 +627,18 @@ begin
     Result := AX * FScale + FOffset;
 end;
 
+procedure TAutoScaleAxisTransform.ClearBounds;
+begin
+  inherited ClearBounds;
+  {$R-}{$Q-}
+  with TAutoScaleTransformData(FDrawData) do begin
+    FMin := Infinity;
+    FMax := NegInfinity;
+    FScale := 1.0;
+  end;
+  {$IFDEF OverflowChecking}{$Q+}{$ENDIF}{$IFDEF RangeChecking}{$R+}{$ENDIF}
+end;
+
 constructor TAutoScaleAxisTransform.Create(AOwner: TComponent);
 begin
   inherited Create(AOwner);
@@ -637,18 +666,6 @@ begin
   Result := MinValue <> 0.0;
 end;
 
-procedure TAutoScaleAxisTransform.SetChart(AChart: TObject);
-begin
-  inherited SetChart(AChart);
-  {$R-}{$Q-}
-  with TAutoScaleTransformData(FDrawData) do begin
-    FMin := Infinity;
-    FMax := NegInfinity;
-    FScale := 1.0;
-  end;
-  {$IFDEF OverflowChecking}{$Q+}{$ENDIF}{$IFDEF RangeChecking}{$R+}{$ENDIF}
-end;
-
 procedure TAutoScaleAxisTransform.SetMaxValue(const AValue: Double);
 begin
   if FMaxValue = AValue then exit;