These two classes make it easier to lay objects out on a screen. The first class is the wxMultiCellCanvas, which uses the wxFlexGridSizer control, so it is subject to the same limitations of that control. Among them is the fact that if the window is resized smaller than the control, then some of the objects will be obscured by the window edge. The second class is the wxMultiCellSizer, which is significantly more powerful than the wxMultiCell Canvas. This control supports resizing of objects on the fly, objects spanning cells, etc. Use the wxMultiCellCanvas when you have a simple layout which won't resize and doesn't have any unusual requirements. Use the wxMultiCellSizer when your needs are greater wxMultiCellCanvas ================= The wxMultiCellCanvas class allows you to add objects to a wxFlexGridSizer by specifying a row and a column location. When all objects have been added, you need to call a member function CalculateConstraints(), which will insert the objects into the wxFlexGridSizer. If there are empty cells the canvas will insert empty wxStaticText objects as placeholders. Upon creation of the canvas the size of the canvas needs to be specified. Attempting to insert a cell outside those limits will cause an assertion error. When adding cells, the cell locations are specified as a row,column location, both being zero-based. 0,0 is the upper left corner of the canvas. wxMultiCellSizer ================ The wxMultiCellSizer class manages a collection of child windows in a way similar to that of data stored in a spreadsheet. A multicell canvas is a two-dimensional array of cells with an origin of (0,0) in the upper-left corner. Windows are added to a multicell sizer by first creating a wxMultiCellItemHandle object which specifies a starting cell and, optionally, a number of contiguous columns, rows, or a combination thereof, and then adding it to the sizer. This class bases the initial cell sizes on the minimum sizes returned by each child window of the sizer. You can override the minimum sizes provided by the wxWindows Class Library by doing either of the following: o Specifying the size when creating the wxMultiCellItemHandle object o Creating a derived class and implementing a CalcMin function The wxMultiCellItemHandle must be passed the row and column of the item, at a minimum. Optionally, more information can be passed: int row Row position, zero based int column Column position, zero based int height Number of rows this cell will occupy, default is 1 int width Number of columns this cell will occupy, default is 1 Note that if the height or width is greater than one that dimension is assumed to be resizable because it is spanning multiple cells. wxSize minSize Minimum size of the object. wxResizable Style Is this object resizable, and if so, how. Allowable styles are: wxNOT_RESIZABLE wxHORIZENTAL_RESIZABLE wxVERTICAL_RESIZABLE wxRESIZABLE wxSize weight If this is a resizable object, the weight applied to the specific dimension. This is useful if you have several resizable rows and/or columns, and you want one to get more of the available space than the others. int align This is a wxAlignment value, it is an integer so you can 'or multiple values together. The acceptable values are: wxALIGN_NOT wxALIGN_CENTER_HORIZONTAL wxALIGN_CENTRE_HORIZONTAL wxALIGN_LEFT wxALIGN_TOP wxALIGN_RIGHT wxALIGN_BOTTOM wxALIGN_CENTER_VERTICAL wxALIGN_CENTRE_VERTICAL wxALIGN_CENTER wxALIGN_CENTRE Note that some combinations of these make no sense, for example wxALIGN_LEFT | wxALIGN_RIGHT. See the definition of wxAlignment for more information Other functions are: void RecalcSizes() Should not be called by the user, needed by the wxSizer class wxSize CalcMin() Should not be called by the user, needed by the wxSizer class bool SetDefaultCellSize Set the default cell size of an empty cell bool SetColumnWidth Set the width of a column, optionally specifying it as resizable bool SetRowHeight Set the height of a row, optionally specifying it as resizable Sometimes it can be very confusing to determine the relationship between rows, columns, and which ones are resizable or not. Three functions are supplied to make this easier: bool EnableGridLines(wxWindow *win); Call this to either enable or disable the grid lines. Pass the window the sizer is on, or NULL to disable. Currently the window is not used, but it may be in the future. bool SetGridPen(wxPen *pen); Set the pen color, the default pen color is red void OnPaint(wxDC& dc); Call this from an OnPaint function associated with the window the sizer is attached to. See the example program mtest.cpp for specific details on how to do this. Files Description ===== =========== docs.txt This file // wxMultiCellCanvas and wxMultiCellSizer makefile Makefile for the MingW32 compiler multicell.cpp Class source code file multicell.h Class header file //Sample mtest.cpp Example program, demonstrates both classes mtest.rc mtest.gif makefile Acknowledgments =============== This was inspired by the gbsizer class written by Alex Andruschak, and the IMultiCellCanvas class in the IBM Class Libraries in the VisualeAge C++ compilers.