From 1f99cf0ccfee9c58f46d766f41137bdf61be2b76 Mon Sep 17 00:00:00 2001
From: ask <ask@lazarus-ide.org>
Date: Mon, 24 Jan 2011 08:51:05 +0000
Subject: [PATCH] TAChart: Support multi-line mark labels

git-svn-id: trunk@29183 -
---
 components/tachart/tadrawutils.pas | 55 ++++++++++++++++++++++++++++--
 components/tachart/tatypes.pas     |  8 ++---
 2 files changed, 57 insertions(+), 6 deletions(-)

diff --git a/components/tachart/tadrawutils.pas b/components/tachart/tadrawutils.pas
index 87957afc4f..3c1c32977d 100644
--- a/components/tachart/tadrawutils.pas
+++ b/components/tachart/tadrawutils.pas
@@ -21,7 +21,7 @@ unit TADrawUtils;
 interface
 
 uses
-  Classes, Graphics, SysUtils;
+  Classes, Graphics, SysUtils, Types;
 
 const
   Colors: array [1..15] of TColor = (
@@ -48,6 +48,9 @@ type
 procedure DrawLineDepth(ACanvas: TCanvas; AX1, AY1, AX2, AY2, ADepth: Integer);
 procedure DrawLineDepth(ACanvas: TCanvas; const AP1, AP2: TPoint; ADepth: Integer);
 
+function MultiLineTextExtent(ACanvas: TCanvas; const AText: String): TPoint;
+procedure MultiLineTextOut(ACanvas: TCanvas; APos: TPoint; const AText: String);
+
 procedure PrepareSimplePen(ACanvas: TCanvas; AColor: TColor);
 procedure PrepareXorPen(ACanvas: TCanvas);
 
@@ -56,7 +59,7 @@ function TypicalTextHeight(ACanvas: TCanvas): Integer;
 implementation
 
 uses
-  Types, TAChartUtils;
+  Math, TAChartUtils;
 
 procedure DrawLineDepth(ACanvas: TCanvas; AX1, AY1, AX2, AY2, ADepth: Integer);
 begin
@@ -72,6 +75,54 @@ begin
   ACanvas.Polygon([AP1, AP1 + d, AP2 + d, AP2]);
 end;
 
+const
+  LINE_INTERVAL = 2;
+
+function MultiLineTextExtent(ACanvas: TCanvas; const AText: String): TPoint;
+var
+  sl: TStrings;
+  i: Integer;
+begin
+  if Pos(LineEnding, AText) = 0 then
+    exit(ACanvas.TextExtent(AText));
+  sl := TStringList.Create;
+  try
+    sl.Text := AText;
+    Result := Size(0, -LINE_INTERVAL);
+    for i := 0 to sl.Count - 1 do
+      with ACanvas.TextExtent(sl[i]) do begin
+        Result.X := Max(Result.X, cx);
+        Result.Y += cy + LINE_INTERVAL;
+      end;
+  finally
+    sl.Free;
+  end;
+end;
+
+procedure MultiLineTextOut(ACanvas: TCanvas; APos: TPoint; const AText: String);
+var
+  sl: TStrings;
+  i, h: Integer;
+  a: Double;
+begin
+  if Pos(LineEnding, AText) = 0 then begin
+    ACanvas.TextOut(APos.X, APos.Y, AText);
+    exit;
+  end;
+  a := -OrientToRad(ACanvas.Font.Orientation);
+  sl := TStringList.Create;
+  try
+    sl.Text := AText;
+    for i := 0 to sl.Count - 1 do begin
+      ACanvas.TextOut(APos.X, APos.Y, sl[i]);
+      h := ACanvas.TextHeight(sl[i]) + LINE_INTERVAL;
+      APos += RotatePoint(Point(0, h), a);
+    end;
+  finally
+    sl.Free;
+  end;
+end;
+
 procedure PrepareSimplePen(ACanvas: TCanvas; AColor: TColor);
 begin
   with ACanvas.Pen do begin
diff --git a/components/tachart/tatypes.pas b/components/tachart/tatypes.pas
index 9b0cb2e164..a6762e4808 100644
--- a/components/tachart/tatypes.pas
+++ b/components/tachart/tatypes.pas
@@ -308,7 +308,7 @@ type
 implementation
 
 uses
-  TACustomSource;
+  TACustomSource, TADrawUtils;
 
 { TChartPen }
 
@@ -511,7 +511,7 @@ var
   i: Integer;
 begin
   PutLabelFontTo(ACanvas);
-  ptText := ACanvas.TextExtent(AText);
+  ptText := MultiLineTextExtent(ACanvas, AText);
   labelPoly := GetLabelPolygon(ptText);
   for i := 0 to High(labelPoly) do
     labelPoly[i] += ALabelCenter;
@@ -537,7 +537,7 @@ begin
   end;
 
   ptText := RotatePoint(-ptText div 2, LabelAngle) + ALabelCenter;
-  ACanvas.TextOut(ptText.X, ptText.Y, AText);
+  MultiLineTextOut(ACanvas, ptText, AText);
   if wasClipping then
     ACanvas.Clipping := true;
 end;
@@ -588,7 +588,7 @@ var
   sz: TPoint;
 begin
   PutLabelFontTo(ACanvas);
-  sz := ACanvas.TextExtent(AText);
+  sz := MultiLineTextExtent(ACanvas, AText);
   if IsMarginRequired then
     sz += Point(MARKS_MARGIN_X, MARKS_MARGIN_Y) * 2;
   Result := MeasureRotatedRect(sz, LabelAngle);