wxGrid size (height) is too small in a sizer

[tan]

wxGrid has too small height in a sizer. To reproduce set initial size for grid to default wxSize(-1, -1) in the grid sample (patch included).

[VZ]

(In [72704]) Invalidate wxGrid best size when the grid is changed.

Don't keep using the cached best size if rows/columns are added/removed
to/from wxGrid or resized, doing this meant that we always used the first
computed best size which was way too small after adding rows/columns to the
grid.

There could be more places where the grid best size may need to be invalidated
but this should be a good start.

Closes #14761.

[llbatlle]

I'm testing r73155, in a code like this:

                _grid = new wxGrid(this, -1);
                _grid->CreateGrid(4, 2);
                _grid->SetColLabelValue(0, _T("Y"));
                _grid->SetColLabelValue(1, _T("Z"));

                /* Required at wx r73155, but wasn't required at
                   wx r72143. No idea why. */
                _grid->InvalidateBestSize();

Notice the InvalidateBestSize() I've had to add since our last wx code use. Without this, the grid gets a very small size, with scrollbars.

I think this ticket is related, so I reopen it.

[hackish]

I agree and I can probably fix this. There are additional items that need to be properly tested and debugged. I'd like to do that first before creating and submitting a patch that fixes this and other issues.

[vadz]

AFAICS, we just need to invalidate the best size when changing the table. Not sure how it worked before without this to be honest but at least doing this fixes the following test case which didn't work before but does now:

samples/minimal/minimal.cpp

@@ -30 +30 @@
     #include "wx/wx.h"
 #endif
 
+#include "wx/grid.h"
+
 // ----------------------------------------------------------------------------
 // resources
 // ----------------------------------------------------------------------------
@@ -167 +169 @@
     SetMenuBar(menuBar);
 #endif // wxUSE_MENUS
 
+    wxSizer* sizer = new wxBoxSizer(wxVERTICAL);
+    sizer->Add(new wxStaticText(this, wxID_ANY, "This is a grid"));
+
+    wxGrid* g = new wxGrid(this, wxID_ANY, wxPoint(10, 40));
+    g->CreateGrid(4, 2);
+    g->SetColLabelValue(0, "Y");
+    g->SetColLabelValue(1, "Z");
+    sizer->Add(g);
+    SetSizer(sizer);
+
 #if wxUSE_STATUSBAR
     // create a status bar just for fun (by default with 1 pane only)
     CreateStatusBar(2);

so I'll commit this soon.

[VZ]

(In [73243]) Invalidate wxGrid best size when its associated table changes.

The number of grid cells changes too, so the old best size can't be used any
more.

Closes #14761.