The basic idea behind a box sizer is that windows will most often be laid out in rather
simple basic geometry, typically in a row or a column or several hierarchies of either.
-As an example, we will construct a dialog that will contain a text field at the top and
-two buttons at the bottom. This can be seen as a top-hierarchy column with the text at
-the top and buttons at the bottom and a low-hierarchy row with an OK button to the left
-and a Cancel button to the right. In many cases (particularly dialogs under Unix and
-normal frames) the main window will be resizable by the user and this change of size
-will have to get propagated to its children. In our case, we want the text area to grow
-with the dialog, whereas the button shall have a fixed size. In addition, there will be
-a thin border around all controls to make the dialog look nice and - to make matter worse -
-the buttons shall be centred as the width of the dialog changes.
-
-It is the unique feature of a box sizer, that it can grow in both directions (height and
-width) but can distribute its growth in the main direction (horizontal for a row) {\it unevenly}
-among its children. In our example case, the vertical sizer is supposed to propagate all its
-height changes to only the text area, not to the button area. This is determined by the {\it option} parameter
-when adding a window (or another sizer) to a sizer. It is interpreted
-as a weight factor, i.e. it can be zero, indicating that the window may not be resized
-at all, or above zero. If several windows have a value above zero, the value is interpreted
-relative to the sum of all weight factors of the sizer, so when adding two windows with
-a value of 1, they will both get resized equally much and each half as much as the sizer
-owning them. Then what do we do when a column sizer changes its width? This behaviour is
-controlled by {\it flags} (the second parameter of the Add() function): Zero or no flag
-indicates that the window will preserve it is original size, wxGROW flag (same as wxEXPAND)
-forces the window to grow with the sizer, and wxSHAPED flag tells the window to change it is
-size proportionally, preserving original aspect ratio. When wxGROW flag is not used,
-the item can be aligned within available space. wxALIGN\_LEFT, wxALIGN\_TOP, wxALIGN\_RIGHT,
-wxALIGN\_BOTTOM, wxALIGN\_CENTER\_HORIZONTAL and wxALIGN\_CENTER\_VERTICAL do what they say.
-wxALIGN\_CENTRE (same as wxALIGN\_CENTER) is defined as (wxALIGN\_CENTER\_HORIZONTAL |
-wxALIGN\_CENTER\_VERTICAL). Default alignment is wxALIGN\_LEFT | wxALIGN\_TOP.
-
-As mentioned above, any window belonging to a sizer may have border, and it can be specified
-which of the four sides may have this border, using the wxTOP, wxLEFT, wxRIGHT and wxBOTTOM
-constants or wxALL for all directions (and you may also use wxNORTH, wxWEST etc instead). These
-flags can be used in combination with the alignment flags above as the second parameter of the
-Add() method using the binary or operator |. The sizer of the border also must be made known,
-and it is the third parameter in the Add() method. This means, that the entire behaviour of
-a sizer and its children can be controlled by the three parameters of the Add() method.
-
-\begin{verbatim}
-// we want to get a dialog that is stretchable because it
-// has a text ctrl at the top and two buttons at the bottom
-
-MyDialog::MyDialog(wxFrame *parent, wxWindowID id, const wxString &title )
- : wxDialog(parent, id, title, wxDefaultPosition, wxDefaultSize,
- wxDEFAULT_DIALOG_STYLE | wxRESIZE_BORDER)
-{
- wxBoxSizer *topsizer = new wxBoxSizer( wxVERTICAL );
-
- // create text ctrl with minimal size 100x60
- topsizer->Add(
- new wxTextCtrl( this, -1, "My text.", wxDefaultPosition, wxSize(100,60), wxTE_MULTILINE),
- 1, // make vertically stretchable
- wxEXPAND | // make horizontally stretchable
- wxALL, // and make border all around
- 10 ); // set border width to 10
-
-
- wxBoxSizer *button_sizer = new wxBoxSizer( wxHORIZONTAL );
- button_sizer->Add(
- new wxButton( this, wxID_OK, "OK" ),
- 0, // make horizontally unstretchable
- wxALL, // make border all around (implicit top alignment)
- 10 ); // set border width to 10
- button_sizer->Add(
- new wxButton( this, wxID_CANCEL, "Cancel" ),
- 0, // make horizontally unstretchable
- wxALL, // make border all around (implicit top alignment)
- 10 ); // set border width to 10
-
- topsizer->Add(
- button_sizer,
- 0, // make vertically unstretchable
- wxALIGN_CENTER ); // no border and centre horizontally
-
- SetAutoLayout( TRUE ); // tell dialog to use sizer
- SetSizer( topsizer ); // actually set the sizer
-
- topsizer->Fit( this ); // set size to minimum size as calculated by the sizer
- topsizer->SetSizeHints( this ); // set size hints to honour mininum size
-}
-\end{verbatim}
+For more information, please see \helpref{Programming with wxBoxSizer}{boxsizerprogramming}.
\wxheading{Derived from}
\helpref{wxSizer}{wxsizer}\\
\helpref{wxObject}{wxobject}
+\wxheading{Include files}
+
+<wx/sizer.h>
+
+\wxheading{See also}
+
+\helpref{wxSizer}{wxsizer}, \helpref{Sizer overview}{sizeroverview}
+
\membersection{wxBoxSizer::wxBoxSizer}\label{wxboxsizerwxboxsizer}
\func{}{wxBoxSizer}{\param{int }{orient}}
\func{void}{RecalcSizes}{\void}
Implements the calculation of a box sizer's dimensions and then sets
-the size of its its children (calling \helpref{wxWindow::SetSize}{wxwindowsetsize}
+the size of its children (calling \helpref{wxWindow::SetSize}{wxwindowsetsize}
if the child is a window). It is used internally only and must not be called
by the user. Documented for information.
projects / wxWidgets.git / blobdiff