TAChart: Add event OnHintLocation to TDataPointHintTool which knows the size of the hint window (OnHintPosition is deprecated now). Update "financial" demo to show hint window above data points.

git-svn-id: trunk@46272 -
2025-04-10 17:48:16 +02:00 · 2014-09-21 14:42:10 +00:00 · 2014-09-21 14:42:10 +00:00 · c97e37c258
commit c97e37c258
parent 05710323ef
5 changed files with 102 additions and 25 deletions
--- a/components/tachart/demo/financial/financialdemo.lpi
+++ b/components/tachart/demo/financial/financialdemo.lpi
@ -9,7 +9,6 @@
      <Title Value="financialdemo"/>
      <ResourceType Value="res"/>
      <UseXPManifest Value="True"/>
-      <Icon Value="0"/>
    </General>
    <i18n>
      <EnableI18N LFM="False"/>
--- a/components/tachart/demo/financial/main.lfm
+++ b/components/tachart/demo/financial/main.lfm
@ -2,28 +2,28 @@ object MainForm: TMainForm
  Left = 313
  Height = 438
  Top = 177
-  Width = 758
+  Width = 891
  Caption = 'MainForm'
  ClientHeight = 438
-  ClientWidth = 758
+  ClientWidth = 891
  OnCreate = FormCreate
  LCLVersion = '1.3'
  object TopPanel: TPanel
    Left = 0
    Height = 42
    Top = 0
-    Width = 758
+    Width = 891
    Align = alTop
    BevelOuter = bvNone
    ClientHeight = 42
-    ClientWidth = 758
+    ClientWidth = 891
    TabOrder = 0
    object cbSeriesType: TComboBox
      Left = 8
-      Height = 28
+      Height = 23
      Top = 8
      Width = 242
-      ItemHeight = 20
+      ItemHeight = 15
      ItemIndex = 0
      Items.Strings = (
        'OHLC series'
@ -34,12 +34,20 @@ object MainForm: TMainForm
      TabOrder = 0
      Text = 'OHLC series'
    end
+    object Label1: TLabel
+      Left = 266
+      Height = 15
+      Top = 12
+      Width = 523
+      Caption = 'Hold the left mouse button down to see a hint window with the stock prices above each data point.'
+      ParentColor = False
+    end
  end
  object FinancialChart: TChart
    Left = 0
    Height = 396
    Top = 42
-    Width = 758
+    Width = 891
    AxisList = <    
      item
        Grid.Color = clSilver
@ -70,6 +78,7 @@ object MainForm: TMainForm
    Title.Text.Strings = (
      'TAChart'
    )
+    Toolset = ChartToolset1
    Align = alClient
    ParentColor = False
    object ohlcSeries: TOpenHighLowCloseSeries
@ -82,4 +91,15 @@ object MainForm: TMainForm
      Mode = mOHLC
    end
  end
+  object ChartToolset1: TChartToolset
+    left = 160
+    top = 111
+    object DataPointHintTool: TDataPointHintTool
+      Shift = [ssLeft]
+      DistanceMode = cdmOnlyX
+      GrabRadius = 8
+      OnHint = DataPointHintToolHint
+      OnHintLocation = DataPointHintToolHintLocation
+    end
+  end
 end
--- a/components/tachart/demo/financial/main.pas
+++ b/components/tachart/demo/financial/main.pas
@ -5,8 +5,8 @@ unit main;
 interface

 uses
-  Classes, SysUtils, FileUtil, TAGraph, TASources, TAMultiSeries, Forms,
-  Controls, Graphics, Dialogs, ExtCtrls, StdCtrls;
+  Classes, SysUtils, FileUtil, TAGraph, TAMultiSeries, TATools,
+  Forms, Controls, Graphics, Dialogs, ExtCtrls, StdCtrls, types;

 type

@ -14,10 +14,17 @@ type

  TMainForm = class(TForm)
    cbSeriesType: TComboBox;
+    ChartToolset1: TChartToolset;
+    DataPointHintTool: TDataPointHintTool;
    FinancialChart: TChart;
+    Label1: TLabel;
    ohlcSeries: TOpenHighLowCloseSeries;
    TopPanel: TPanel;
    procedure cbSeriesTypeChange(Sender: TObject);
+    procedure DataPointHintToolHint(ATool: TDataPointHintTool;
+      const APoint: TPoint; var AHint: String);
+    procedure DataPointHintToolHintLocation(ATool: TDataPointHintTool;
+      AHintSize: TSize; var APoint: TPoint);
    procedure FormCreate(Sender: TObject);
  private
    { private declarations }
@ -53,19 +60,6 @@ begin
  fs.DateSeparator := '-';
  fs.ShortDateFormat := 'd/mmm/yyyy';
  fs.DecimalSeparator := '.';
-  fs.ShortMonthNames[1] := 'Jan';
-  fs.ShortMonthNames[2] := 'Feb';
-  fs.ShortMonthNames[3] := 'Mar';
-  fs.ShortMonthNames[4] := 'Apr';
-  fs.ShortMonthNames[5] := 'May';
-  fs.ShortMonthNames[6] := 'Jun';
-  fs.ShortMonthNames[7] := 'Jul';
-  fs.ShortMonthNames[8] := 'Aug';
-  fs.ShortMonthNames[9] := 'Sep';
-  fs.ShortMonthNames[10] := 'Oct';
-  fs.ShortMonthNames[11] := 'Nov';
-  fs.ShortMonthNames[12] := 'Dec';
-
  dataList := TStringList.Create;
  try
    dataList.LoadFromFile(DATA_FILE);
@ -81,7 +75,7 @@ begin
        // We don't use the date for x because we want to skip the weekends in the chart
        // Therefore, we use the index and add the date as a label. Diplay of
        // the data labels is activated by BottomAxis.Marks.Style = smsLabel.
-        ohlcSeries.AddXOHLC(i, yOpen, yHigh, yLow, yClose, DateToStr(xDate, fs));
+        ohlcSeries.AddXOHLC(i, yOpen, yHigh, yLow, yClose, DateToStr(xDate));
      end;
    finally
      lines.Free;
@ -93,10 +87,57 @@ begin
  FinancialChart.BottomAxis.Marks.Source := ohlcSeries.ListSource;
 end;

+{ The combobox switches between OHLC and candle stick display modes. }
 procedure TMainForm.cbSeriesTypeChange(Sender: TObject);
 begin
  ohlcSeries.Mode := TOHLCMode(CbSeriesType.ItemIndex);
 end;

+{ This event handler returns the text to be displayed as a mouse-over hint.
+  We construct the text from the date, and the open, high, low, close values. }
+procedure TMainForm.DataPointHintToolHint(ATool: TDataPointHintTool;
+  const APoint: TPoint; var AHint: String);
+var
+  ser: TOpenHighLowCloseSeries;
+begin
+  ser := ATool.Series as TOpenHighLowCloseSeries;
+  AHint := AnsiToUTF8(Format('Date: %s'#13'  Open: %.2m'#13'  High: %.2m'#13'  Low: %.2m'#13'  Close: %.2m', [
+    FormatDateTime('dddddd', StrToDate(ser.ListSource[ATool.PointIndex]^.Text)),
+    ser.ListSource[ATool.PointIndex]^.YList[0],
+    ser.ListSource[ATool.PointIndex]^.YList[2],
+    ser.ListSource[ATool.PointIndex]^.Y,
+    ser.ListSource[ATool.PointIndex]^.YList[1]
+  ]));
+end;
+
+{ This event handler returns the location of the hint on the screen. To enhance
+  the assosciation with the data point and to avoid covering of the data point
+  we move center the hint window and move it up to the top of a OHLC/candle
+  data point.
+
+  Note:
+  The tool's UseApplicationHint must be set to FALSE for this even to fire. }
+procedure TMainForm.DataPointHintToolHintLocation(ATool: TDataPointHintTool;
+  AHintSize: TSize; var APoint: TPoint);
+var
+  ser: TOpenHighLowCloseSeries;
+  x, y: Integer;
+begin
+  { Calculate screen coordinates of the "high" point }
+  ser := ATool.Series as TOpenHighLowCloseSeries;
+  x := FinancialChart.XGraphToImage(ser.ListSource[ATool.PointIndex]^.X);
+  y := FinancialChart.YGraphToImage(ser.ListSource[ATool.PointIndex]^.YList[2]);
+    // "High" value, i.e. max of data point
+
+  // Center hint horizontally relative to data point
+  APoint.x := x - AHintSize.CX div 2;
+
+  // Move hint 4 pixels above the "High" data point
+  APoint.y := y - AHintSize.CY - 4;
+
+  // Hint coordinates are relative to screen
+  APoint := FinancialChart.ClientToScreen(APoint);
+end;
+
 end.

--- a/components/tachart/tachartlazaruspkg.lpk
+++ b/components/tachart/tachartlazaruspkg.lpk
@ -22,6 +22,11 @@
          <RangeChecks Value="True"/>
        </Checks>
      </CodeGeneration>
+      <Linking>
+        <Debugging>
+          <DebugInfoType Value="dsDwarf2"/>
+        </Debugging>
+      </Linking>
    </CompilerOptions>
    <Description Value="TeeChart compatible graph component"/>
    <License Value=" See the file COPYING.modifiedLGPL, included in this distribution,
--- a/components/tachart/tatools.pas
+++ b/components/tachart/tatools.pas
@ -473,6 +473,9 @@ type
  TChartToolHintPositionEvent = procedure (
    ATool: TDataPointHintTool; var APoint: TPoint) of object;

+  TChartToolHintLocationEvent = procedure (
+    ATool: TDataPointHintTool; AHintSize: TSize; var APoint: TPoint) of object;
+
  { TDataPointHintTool }

  TDataPointHintTool = class(TDataPointTool)
@ -480,6 +483,7 @@ type
    FHintWindow: THintWindow;
    FOnHint: TChartToolHintEvent;
    FOnHintPosition: TChartToolHintPositionEvent;
+    FOnHintLocation: TChartToolHintLocationEvent;
    FPrevPointIndex: Integer;
    FPrevSeries: TBasicChartSeries;
    FUseApplicationHint: Boolean;
@ -497,8 +501,10 @@ type
  published
    property ActiveCursor;
    property OnHint: TChartToolHintEvent read FOnHint write FOnHint;
+    property OnHintLocation: TChartToolHintLocationEvent
+      read FOnHintLocation write FOnHintLocation;
    property OnHintPosition: TChartToolHintPositionEvent
-      read FOnHintPosition write FOnHintPosition;
+      read FOnHintPosition write FOnHintPosition; deprecated;
    property UseApplicationHint: Boolean
      read FUseApplicationHint write SetUseApplicationHint default false;
    property UseDefaultHintText: Boolean
@ -1770,6 +1776,7 @@ procedure TDataPointHintTool.MouseMove(APoint: TPoint);
 var
  r: TRect;
  h: String;
+  sz: TSize;
 begin
  FSeries := nil;
  FindNearestPoint(APoint);
@ -1800,6 +1807,11 @@ begin
      FHintWindow := THintWindow.Create(nil);
    if h = '' then exit;
    r := FHintWindow.CalcHintRect(FChart.Width, h, Nil);
+    if Assigned(OnHintLocation) then begin
+      sz.CX := r.Right - r.Left;
+      sz.CY := r.Bottom - r.Top;
+      OnHintLocation(Self, sz, APoint);
+    end;
    OffsetRect(r, APoint.X, APoint.Y);
    FHintWindow.ActivateWithBounds(r, h);
  end;