From ce34aeb40519c70be4020583f4b44f445947869a Mon Sep 17 00:00:00 2001
From: wp_xxyyzz <wp_xxyyzz@8e941d3f-bd1b-0410-a28a-d453659cc2b4>
Date: Mon, 15 Sep 2014 07:33:55 +0000
Subject: [PATCH] fpspreadsheet: Fix new TsWorksheetGrid crashing without
 workbook.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@3567 8e941d3f-bd1b-0410-a28a-d453659cc2b4
---
 .../examples/fpsgrid_no_install/mainfrm.lfm       |  4 ++--
 .../examples/fpsgrid_no_install/mainfrm.pas       | 14 +++++++++-----
 components/fpspreadsheet/fpspreadsheetgrid.pas    | 15 ++++++++++-----
 3 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/components/fpspreadsheet/examples/fpsgrid_no_install/mainfrm.lfm b/components/fpspreadsheet/examples/fpsgrid_no_install/mainfrm.lfm
index 833da40ca..c6d3c1932 100644
--- a/components/fpspreadsheet/examples/fpsgrid_no_install/mainfrm.lfm
+++ b/components/fpspreadsheet/examples/fpsgrid_no_install/mainfrm.lfm
@@ -32,7 +32,7 @@ object Form1: TForm1
       Height = 25
       Top = 6
       Width = 75
-      Caption = 'Load'
+      Caption = 'Load...'
       OnClick = BtnLoadClick
       TabOrder = 1
     end
@@ -41,7 +41,7 @@ object Form1: TForm1
       Height = 25
       Top = 6
       Width = 75
-      Caption = 'Save'
+      Caption = 'Save...'
       OnClick = BtnSaveClick
       TabOrder = 2
     end
diff --git a/components/fpspreadsheet/examples/fpsgrid_no_install/mainfrm.pas b/components/fpspreadsheet/examples/fpsgrid_no_install/mainfrm.pas
index 27547b546..4126e0909 100644
--- a/components/fpspreadsheet/examples/fpsgrid_no_install/mainfrm.pas
+++ b/components/fpspreadsheet/examples/fpsgrid_no_install/mainfrm.pas
@@ -47,15 +47,19 @@ procedure TForm1.FormCreate(Sender: TObject);
 begin
   Grid := TsWorksheetGrid.Create(self);
 
-  // Put the grid into the TabControl
+  // Put the grid into the TabControl and align it to fill the tabcontrol.
   Grid.Parent := TabControl;
   Grid.Align := alClient;
 
   // Useful options
-  Grid.Options := Grid.Options + [goColSizing, goRowSizing, goEditing, goThumbTracking];
-  Grid.AutoAdvance := aaDown;
-  Grid.MouseWheelOption := mwGrid;
-  Grid.TextOverflow := true;
+  Grid.Options := Grid.Options + [goColSizing, goRowSizing,
+    goFixedColSizing,  // useful if the spreadsheet contains frozen columns
+    goEditing,         // needed for modifying cell content
+    goThumbTracking    // see the grid scroll while you drag the scrollbar
+  ];
+  Grid.AutoAdvance := aaDown;       // move active cell down on ENTER
+  Grid.MouseWheelOption := mwGrid;  // mouse wheel scrolls the grid, not the active cell
+  Grid.TextOverflow := true;        // too long text extends into neighbor cells
 
   // Create an empty worksheet
   Grid.NewWorkbook(26, 100);
diff --git a/components/fpspreadsheet/fpspreadsheetgrid.pas b/components/fpspreadsheet/fpspreadsheetgrid.pas
index 8d332400e..ac89308d6 100644
--- a/components/fpspreadsheet/fpspreadsheetgrid.pas
+++ b/components/fpspreadsheet/fpspreadsheetgrid.pas
@@ -1469,7 +1469,6 @@ begin
   end;
 
   sr := GetWorksheetRow(ARow);
-  gcLastUsed := GetGridCol(FWorksheet.GetLastOccupiedColIndex);
 
   // Draw columns in this row
   with GCache.VisibleGrid do
@@ -1479,7 +1478,7 @@ begin
     // Because of possible cell overflow from cells left of the visible range
     // we have to seek to the left for the first occupied text cell
     // and start painting from here.
-    if FTextOverflow and (sr <> Cardinal(-1)) then
+    if FTextOverflow and (sr <> Cardinal(-1)) and Assigned(FWorksheet) then
       while (gc > FixedCols) do
       begin
         dec(gc);
@@ -1503,7 +1502,9 @@ begin
     // Now find the last column. Again text can overflow into the visible area
     // from cells to the right.
     gcLast := Right;
-    if FTextOverflow and (sr <> Cardinal(-1)) then
+    if FTextOverflow and (sr <> Cardinal(-1)) and Assigned(FWorksheet) then
+    begin
+      gcLastUsed := GetGridCol(FWorksheet.GetLastOccupiedColIndex);
       while (gcLast < ColCount-1) and (gcLast < gcLastUsed) do begin
         inc(gcLast);
         cell := FWorksheet.FindCell(sr, GetWorksheetCol(gcLast));
@@ -1522,6 +1523,7 @@ begin
         gcLast := Right;
         Break;
       end;
+    end;
 
     while (gc <= gcLast) do begin
       gr := ARow;
@@ -1530,7 +1532,7 @@ begin
       // it to avoid excessive calls to "FindCell".
       FDrawingCell := nil;
       gcNext := gc + 1;
-      if (FWorksheet <> nil) and (gr >= FixedRows) and (gc >= FixedCols) then
+      if Assigned(FWorksheet) and (gr >= FixedRows) and (gc >= FixedCols) then
       begin
         cell := FWorksheet.FindCell(GetWorksheetRow(gr), GetWorksheetCol(gc));
         if (cell = nil) or (cell^.MergedNeighbors = []) then begin
@@ -1599,7 +1601,10 @@ begin
     // is this column within the ClipRect?
     if (rct.Left < rct.Right) and HorizontalIntersect(rct, clipArea) then
     begin
-      FDrawingCell := FWorksheet.FindCell(GetWorksheetRow(gr), GetWorksheetCol(gc));
+      if Assigned(FWorksheet) then
+        FDrawingCell := FWorksheet.FindCell(GetWorksheetRow(gr), GetWorksheetCol(gc))
+      else
+        FDrawingCell := nil;
       DoDrawCell(gc, gr);
     end;
   end;