TAChart: Initial commit of TChartLiveView

git-svn-id: trunk@63737 -

.gitattributes

@@ -5456,6 +5456,7 @@ components/tachart/tachartimagelist.pas svneol=native#text/pascal
 components/tachart/tachartlazaruspkg.lpk svneol=native#text/plain
 components/tachart/tachartlazaruspkg.pas svneol=native#text/plain
 components/tachart/tachartlistbox.pas svneol=native#text/pascal
+components/tachart/tachartliveview.pas svneol=native#text/pascal
 components/tachart/tachartstrconsts.pas svneol=native#text/plain
 components/tachart/tachartteechart.pas svneol=native#text/pascal
 components/tachart/tachartutils.pas svneol=native#text/plain

components/tachart/tachartlazaruspkg.lpk

@@ -30,7 +30,7 @@
  for details about the copyright.
 "/>
     <Version Major="1"/>
-    <Files Count="53">
+    <Files Count="54">
       <Item1>
         <Filename Value="tagraph.pas"/>
         <HasRegisterProc Value="True"/>
@@ -261,6 +261,10 @@
         <Filename Value="tadatapointseditor.pas"/>
         <UnitName Value="TADataPointsEditor"/>
       </Item53>
+      <Item54>
+        <Filename Value="tachartliveview.pas"/>
+        <UnitName Value="TAChartLiveView"/>
+      </Item54>
     </Files>
     <CompatibilityMode Value="True"/>
     <LazDoc Paths="$(LazarusDir)\components\tachart\fpdoc"/>

components/tachart/tachartlazaruspkg.pas

@@ -18,7 +18,8 @@ uses
   TATextElements, TAAxisSource, TASeriesPropEditors, TACustomFuncSeries, 
   TAFitUtils, TAGUIConnector, TADiagram, TADiagramDrawing, TADiagramLayout, 
   TAChartStrConsts, TAChartCombos, TAHtml, TAFonts, TAExpressionSeries, 
-  TAFitLib, TASourcePropEditors, TADataPointsEditor, LazarusPackageIntf;
+  TAFitLib, TASourcePropEditors, TADataPointsEditor, TAChartLiveView, 
+  LazarusPackageIntf;
 
 implementation
 

components/tachart/tachartliveview.pas

@@ -0,0 +1,105 @@
+unit TAChartLiveView;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, TAGraph, TAChartUtils;
+
+type
+  TChartLiveView = class(TComponent)
+  private
+    FActive: Boolean;
+    FChart: TChart;
+    FListener: TListener;
+    FViewportSize: Double;
+    procedure FullExtentChanged(Sender: TObject);
+    procedure SetActive(const AValue: Boolean);
+    procedure SetChart(const AValue: TChart);
+    procedure SetViewportSize(const AValue: Double);
+    procedure UpdateViewport;
+  public
+    constructor Create(AOwner: TComponent); override;
+    destructor Destroy; override;
+  published
+    property Active: Boolean read FActive write SetActive default false;
+    property Chart: TChart read FChart write SetChart default nil;
+    property ViewportSize: double read FViewportSize write SetViewportSize;
+  end;
+
+
+implementation
+
+constructor TChartLiveView.Create(AOwner: TComponent);
+begin
+  inherited;
+  FListener := TListener.Create(@FChart, @FullExtentChanged);
+end;
+
+destructor TChartLiveView.Destroy;
+begin
+  FreeAndNil(FListener);
+  inherited;
+end;
+
+procedure TChartLiveView.FullExtentChanged(Sender: TObject);
+begin
+  if (not FActive) or (FChart = nil) then
+    exit;
+  UpdateViewport;
+end;
+
+procedure TChartLiveView.SetActive(const AValue: Boolean);
+begin
+  if FActive = AValue then exit;
+
+  FActive := AValue;
+  FullExtentChanged(nil);
+end;
+
+procedure TChartLiveView.SetChart(const AValue: TChart);
+begin
+  if FChart = AValue then exit;
+
+  if FListener.IsListening then
+    FChart.FullExtentBroadcaster.Unsubscribe(FListener);
+  FChart := AValue;
+  if FChart <> nil then
+    FChart.FullExtentBroadcaster.Subscribe(FListener);
+  FullExtentChanged(Self);
+end;
+
+procedure TChartLiveView.SetViewportSize(const AValue: Double);
+begin
+  if FViewportSize = AValue then exit;
+
+  FViewportSize := AValue;
+  FullExtentChanged(nil);
+end;
+
+procedure TChartLiveView.UpdateViewport;
+var
+  fext, lext: TDoubleRect;
+  w: double;
+begin
+  fext := FChart.GetFullExtent();
+  lext := FChart.LogicalExtent;
+  w := lext.b.x - lext.a.x;
+  if FViewportSize = 0 then
+    w := lext.b.x - lext.a.x
+  else
+    w := FViewportSize;
+  lext.b.x := fext.b.x;
+  lext.a.x := lext.b.X - w;
+  if lext.a.x < fext.a.x then begin
+    lext.a.x := fext.a.x;
+    lext.b.x := lext.a.x + w;
+  end;
+  lext.a.y := fext.a.y;
+  lext.b.y := fext.b.y;
+  FChart.LogicalExtent := lext;
+end;
+
+end.
+