From bd0f7165d6d68b3707dc8b02d9c7fa4fd39d2450 Mon Sep 17 00:00:00 2001
From: wp_xxyyzz <wp_xxyyzz@8e941d3f-bd1b-0410-a28a-d453659cc2b4>
Date: Mon, 1 Nov 2021 18:59:23 +0000
Subject: [PATCH] ExCtrls: Fix text measuring in TColumnComboBoxEx.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@8140 8e941d3f-bd1b-0410-a28a-d453659cc2b4
---
 components/exctrls/source/excombo.pas | 76 +++++++++++----------------
 1 file changed, 30 insertions(+), 46 deletions(-)

diff --git a/components/exctrls/source/excombo.pas b/components/exctrls/source/excombo.pas
index 8028912dd..d6afb4bcd 100644
--- a/components/exctrls/source/excombo.pas
+++ b/components/exctrls/source/excombo.pas
@@ -48,8 +48,8 @@ type
     FSelectedColor: TColor;
     FSelectedTextColor: TColor;
     FTextHeight: Integer;
+    FNeedMeasure: Boolean;
     function ColumnMarginStored: Boolean;
-    function GetTextSize(const aText: String): TSize;
     function GetColumnCount: Integer;
     function GetDelimiteds(const aLine: String): TStringArray;
     procedure SetColSeparatorColor(AValue: TColor);
@@ -157,6 +157,7 @@ uses
 
 const
   DEFAULT_COLUMN_MARGIN = 4;
+  TEXT_SAMPLE = 'TgjÜ';
 
 { TColumnCombo }
 
@@ -176,6 +177,7 @@ begin
   SetStyle(csOwnerDrawFixed);
   FOffsets := nil;
   FColumnCount := 0;
+  FNeedMeasure := true;
 end;
 
 destructor TColumnComboBoxEx.Destroy;
@@ -186,13 +188,13 @@ end;
 
 function TColumnComboBoxEx.ColumnMarginStored: Boolean;
 begin
-  Result := FColumnMargin <> Scale96ToFont(DEFAULT_COLUMN_MARGIN);
+  Result := FColumnMargin <> DEFAULT_COLUMN_MARGIN;
 end;
 
 procedure TColumnComboBoxEx.CreateHandle;
 begin
   inherited;
-  SetOffsets;
+  FNeedMeasure := true;
 end;
 
 procedure TColumnComboBoxEx.DoAutoAdjustLayout(
@@ -224,6 +226,13 @@ begin
   savedColor := Canvas.Brush.Color;
   savedFontColor := Canvas.Font.Color;
 
+  Canvas.Font.Assign(Font);
+  if FNeedMeasure then begin
+    FTextHeight := Canvas.TextHeight(TEXT_SAMPLE);
+    SetOffsets;
+    FNeedMeasure := false;
+  end;
+
   if DroppedDown then
   begin
     if (odSelected in State) then
@@ -247,7 +256,7 @@ begin
   FParser.Delimiter := FDelimiter;
   FParser.DelimitedText := txt;
 
-  y := ARect.Top + (ARect.Height - FTextHeight) shr 1;
+  y := (ARect.Top + ARect.Bottom - FTextHeight) div 2;
   Canvas.Brush.Style := bsClear;  // transparent text background
   if Assigned(FOffsets) then
   begin
@@ -278,7 +287,7 @@ end;
 procedure TColumnComboBoxEx.FontChanged(Sender: TObject);
 begin
   inherited FontChanged(Sender);
-  FTextHeight := Canvas.TextHeight('ŢÜ');
+  FNeedMeasure := true;
 end;
 
 function TColumnComboBoxEx.GetColumnCount: Integer;
@@ -339,36 +348,12 @@ end;
 procedure TColumnComboBoxEx.GetItems;
 begin
   inherited GetItems;
-//  SetOffsets;
-end;
-
-function TColumnComboBoxEx.GetTextSize(const aText: String): TSize;
-var
-  drawFlags: LongWord = DT_CALCRECT or DT_NOPREFIX or DT_SINGLELINE;
-  r: TRect;
-  dc: HDC;
-begin
-    r.Left := 0;
-    r.Top := 0;
-    dc := GetDC(GetParentForm(Self).Handle);
-    try
-      r.Right := 1000;
-      r.Bottom := 100;
-      DrawText(dc, PChar(aText), Length(aText), r, drawFlags);
-      if r.Right = 1000 then
-        r.Right := 0;
-      if r.Bottom = 100 then
-        r.Bottom := 0;
-      Result.Create(r.Width, r.Height);
-    finally
-      ReleaseDC(Parent.Handle, dc);
-    end;
 end;
 
 procedure TColumnComboBoxEx.InitializeWnd;
 begin
   inherited;
-  SetOffsets;
+  FNeedMeasure := true;
 end;
 
 procedure TColumnComboBoxEx.SetColSeparatorColor(AValue: TColor);
@@ -383,49 +368,48 @@ end;
 procedure TColumnComboBoxEx.SetColumnMargin(aValue: Integer);
 begin
   if FColumnMargin <> aValue then
-    begin
-      FColumnMargin := aValue;
-      Invalidate;
-    end;
+  begin
+    FColumnMargin := aValue;
+    Invalidate;
+  end;
 end;
 
 procedure TColumnComboBoxEx.SetDelimiter(aValue: AnsiChar);
 begin
   if FDelimiter <> aValue then
-    begin
-      FDelimiter := aValue;
-      FColumnCount := GetColumnCount;
-    end;
+  begin
+    FDelimiter := aValue;
+    FColumnCount := GetColumnCount;
+  end;
 end;
 
 procedure TColumnComboBoxEx.SetItems(const Value: TStrings);
 begin
   inherited SetItems(Value);
-  SetOffsets;
+  FNeedMeasure := true;
 end;
 
 procedure TColumnComboBoxEx.SetOffsets;
 var
-  widths: TIntegerDynArray;
+  widths: TIntegerDynArray = nil;
   i, j: Integer;
   sa: TStringArray;
-  sz: TSize;
+  w: Integer;
 begin
   if not Assigned(Parent) or (Items.Count = 0) then
     Exit;
 
   FColumnCount := GetColumnCount;
 
-  SetLength({%H-}widths, FColumnCount);
+  SetLength(widths, FColumnCount);
   for i := 0 to Items.Count-1 do
     begin
       sa := GetDelimiteds(Items[i]);
-      FTextHeight := GetTextSize('ŢÜ').cy;
       for j := 0 to High(sa) do
         begin
-          sz := GetTextSize(sa[j]);
-          if widths[j] < sz.cx then
-            widths[j] := sz.cx;
+          w := Canvas.TextWidth(sa[j]);
+          if widths[j] < w then
+            widths[j] := w;
         end;
     end;
   SetLength(FOffsets, FColumnCount);