From e44c18a3d3b4b1bcb82d9f7d10b0634498a820cd Mon Sep 17 00:00:00 2001
From: ask <ask@lazarus-ide.org>
Date: Wed, 18 Aug 2010 06:32:55 +0000
Subject: [PATCH] TAChart: Implement stacked line series

git-svn-id: trunk@27132 -
---
 components/tachart/tacustomseries.pas |  2 +-
 components/tachart/taseries.pas       | 29 +++++++++++++++------------
 components/tachart/tasources.pas      | 18 +++++++++++++++++
 3 files changed, 35 insertions(+), 14 deletions(-)

diff --git a/components/tachart/tacustomseries.pas b/components/tachart/tacustomseries.pas
index f05e4b4b8a..3deb951858 100644
--- a/components/tachart/tacustomseries.pas
+++ b/components/tachart/tacustomseries.pas
@@ -427,7 +427,7 @@ end;
 
 function TChartSeries.Extent: TDoubleRect;
 begin
-  Result := Source.Extent;
+  Result := Source.ExtentCumulative;
 end;
 
 function TChartSeries.FormattedMark(AIndex: integer): String;
diff --git a/components/tachart/taseries.pas b/components/tachart/taseries.pas
index 2ae6d3f1fa..1cc2b0a4b2 100644
--- a/components/tachart/taseries.pas
+++ b/components/tachart/taseries.pas
@@ -366,16 +366,28 @@ end;
 procedure TLineSeries.Draw(ACanvas: TCanvas);
 var
   ext: TDoubleRect;
+  i, j: Integer;
 begin
-  // Do not draw anything if the series extent does not intersect CurrentExtent.
-  ext.a := AxisToGraph(Source.Extent.a);
-  ext.b := AxisToGraph(Source.Extent.b);
+  with Extent do begin
+    ext.a := AxisToGraph(a);
+    ext.b := AxisToGraph(b);
+  end;
   if LineType = ltFromOrigin then
     ExpandRect(ext, AxisToGraph(ZeroDoublePoint));
+  // Do not draw anything if the series extent does not intersect CurrentExtent.
   if not RectIntersectsRect(ext, ParentChart.CurrentExtent) then exit;
 
   PrepareGraphPoints(ext, LineType <> ltFromOrigin);
   DrawSingleLineInStack(ACanvas);
+  for i := 0 to Source.YCount - 2 do begin
+    if IsRotated then
+      for j := FLoBound to FUpBound do
+        FGraphPoints[j - FLoBound].X += AxisToGraphY(Source[j]^.YList[i])
+    else
+      for j := FLoBound to FUpBound do
+        FGraphPoints[j - FLoBound].Y += AxisToGraphY(Source[j]^.YList[i]);
+    DrawSingleLineInStack(ACanvas);
+  end;
 end;
 
 procedure TLineSeries.DrawSingleLineInStack(ACanvas: TCanvas);
@@ -764,20 +776,11 @@ end;
 
 function TBarSeries.Extent: TDoubleRect;
 var
-  x, h: Double;
-  i, j: Integer;
+  x: Double;
 begin
   Result := inherited Extent;
   if IsEmpty then exit;
   UpdateMinMax(ZeroLevel, Result.a.Y, Result.b.Y);
-  if Source.YCount >= 2 then begin
-    for i := 0 to Count - 1 do begin
-      h := Source[i]^.Y;
-      for j := 0 to Source.YCount - 2 do
-        h += Source[i]^.YList[j];
-      UpdateMinMax(h, Result.a.Y, Result.b.Y);
-    end;
-  end;
   // Show first and last bars fully.
   x := GetGraphPointX(0);
   Result.a.X := Min(Result.a.X, x - CalcBarWidth(x, 0));
diff --git a/components/tachart/tasources.pas b/components/tachart/tasources.pas
index 3a4736c480..8450fea2de 100644
--- a/components/tachart/tasources.pas
+++ b/components/tachart/tasources.pas
@@ -68,6 +68,7 @@ type
   public
     class procedure CheckFormat(const AFormat: String);
     function Extent: TDoubleRect;
+    function ExtentCumulative: TDoubleRect;
     function ExtentList: TDoubleRect;
     procedure FindBounds(AXMin, AXMax: Double; out ALB, AUB: Integer);
     function FormatItem(const AFormat: String; AIndex: Integer): String;
@@ -360,6 +361,23 @@ begin
   Result := FExtent;
 end;
 
+function TCustomChartSource.ExtentCumulative: TDoubleRect;
+var
+  h: Double;
+  i, j: Integer;
+begin
+  Result := Extent;
+  if YCount < 2 then exit;
+  for i := 0 to Count - 1 do begin
+    h := Item[i]^.Y;
+    for j := 0 to YCount - 2 do begin
+      h += Item[i]^.YList[j];
+      // If some of Y values are negative, h may be non-monotonic.
+      UpdateMinMax(h, Result.a.Y, Result.b.Y);
+    end;
+  end;
+end;
+
 function TCustomChartSource.ExtentList: TDoubleRect;
 var
   i, j: Integer;