wxSizer

wxSizer

wxSizer
Functions for wxSizer class

wxSizer is the abstract base class used for laying out subwindows in a window. You cannot use wxSizer directly; instead, you will have to use one of the sizer classes derived from it. Currently there are wxBoxSizer, wxStaticBoxSizer, wxGridSizer, wxFlexGridSizer, wxWrapSizer (not implemented in wx) and wxGridBagSizer.

The layout algorithm used by sizers in wxWidgets is closely related to layout in other GUI toolkits, such as Java's AWT, the GTK toolkit or the Qt toolkit. It is based upon the idea of the individual subwindows reporting their minimal required size and their ability to get stretched if the size of the parent window has changed.

This will most often mean that the programmer does not set the original size of a dialog in the beginning, rather the dialog will be assigned a sizer and this sizer will be queried about the recommended size. The sizer in turn will query its children, which can be normal windows, empty space or other sizers, so that a hierarchy of sizers can be constructed. Note that wxSizer does not derive from wxWindow and thus does not interfere with tab ordering and requires very little resources compared to a real window on screen.

What makes sizers so well fitted for use in wxWidgets is the fact that every control reports its own minimal size and the algorithm can handle differences in font sizes or different window (dialog item) sizes on different platforms without problems. If e.g. the standard font as well as the overall design of Motif widgets requires more space than on Windows, the initial dialog size will automatically be bigger on Motif than on Windows.

Sizers may also be used to control the layout of custom drawn items on the window. The add/4, insert/5, and prepend/4 functions return a pointer to the newly added wxSizerItem. Just add empty space of the desired size and attributes, and then use the wxSizerItem:getRect/1 method to determine where the drawing operations should take place.

Please notice that sizers, like child windows, are owned by the library and will be deleted by it which implies that they must be allocated on the heap. However if you create a sizer and do not add it to another sizer or window, the library wouldn't be able to delete such an orphan sizer and in this, and only this, case it should be deleted explicitly.

wxSizer flags

The "flag" argument accepted by wxSizerItem constructors and other functions, e.g. add/4, is an OR-combination of the following flags. Two main behaviours are defined using these flags. One is the border around a window: the border parameter determines the border width whereas the flags given here determine which side(s) of the item that the border will be added. The other flags determine how the sizer item behaves when the space allotted to the sizer changes, and is somewhat dependent on the specific kind of sizer used.

See: Overview sizer

wxWidgets docs: wxSizer

Types

This = wxSizer()
Window = wxWindow:wxWindow() | wxSizer:wxSizer()
Option =
    {proportion, integer()} |
    {flag, integer()} |
    {border, integer()} |
    {userData, wx:wx_object()}

Appends a child to the sizer.

wxSizer itself is an abstract class, but the parameters are equivalent in the derived classes that you will instantiate to use it so they are described here:

Types

This = wxSizer()
Option = {prop, integer()}

Adds stretchable space to the sizer.

More readable way of calling:

Types

This = wxSizer()

This method is abstract and has to be overwritten by any derived class.

Here, the sizer will do the actual calculation of its children's minimal sizes.

Types

This = wxSizer()
Option = {delete_windows, boolean()}

Detaches all children from the sizer.

If delete_windows is true then child windows will also be deleted.

Notice that child sizers are always deleted, as a general consequence of the principle that sizers own their sizer children, but don't own their window children (because they are already owned by their parent windows).

Types

This = wxSizer()
Index = integer()

Detach a item at position index from the sizer without destroying it.

This method does not cause any layout or resizing to take place, call layout/1 to update the layout "on screen" after detaching a child from the sizer. Returns true if the child item was found and detached, false otherwise.

See: remove/2

Types

This = wxSizer()
Window = wxWindow:wxWindow()

Tell the sizer to resize the window so that its client area matches the sizer's minimal size (ComputeFittingClientSize() (not implemented in wx) is called to determine it).

This is commonly done in the constructor of the window itself, see sample in the description of wxBoxSizer.

Return: The new window size.

See: ComputeFittingClientSize() (not implemented in wx), ComputeFittingWindowSize() (not implemented in wx)

Types

This = wxSizer()
Window = wxWindow:wxWindow()

Tell the sizer to resize the virtual size of the window to match the sizer's minimal size.

This will not alter the on screen size of the window, but may cause the addition/removal/alteration of scrollbars required to view the virtual area in windows which manage it.

See: wxScrolledWindow:setScrollbars/6, setVirtualSizeHints/2

Types

This = wxSizer()

Returns the minimal size of the sizer.

This is either the combined minimal size of all the children and their borders or the minimal size set by setMinSize/3, depending on which is bigger. Note that the returned value is client size, not window size. In particular, if you use the value to set toplevel window's minimal or actual size, use wxWindow::SetMinClientSize() (not implemented in wx) or wxWindow:setClientSize/3, not wxWindow:setMinSize/2 or wxWindow:setSize/6.

Types

This = wxSizer()
Index = integer()

Hides the item at position index.

To make a sizer item disappear, use hide/3 followed by layout/1.

Use parameter recursive to hide elements found in subsizers. Returns true if the child item was found, false otherwise.

See: isShown/2, show/3

Types

This = wxSizer()
Index = integer()
Window = wxWindow:wxWindow() | wxSizer:wxSizer()
Option =
    {proportion, integer()} |
    {flag, integer()} |
    {border, integer()} |
    {userData, wx:wx_object()}

Insert a child into the sizer before any existing item at index.

See add/4 for the meaning of the other parameters.

Types

This = wxSizer()
Index = Size = integer()

Inserts non-stretchable space to the sizer.

More readable way of calling wxSizer::Insert(index, size, size).

Types

This = wxSizer()
Index = integer()
Option = {prop, integer()}

Inserts stretchable space to the sizer.

More readable way of calling wxSizer::Insert(0, 0, prop).

Types

This = wxSizer()

Call this to force layout of the children anew, e.g. after having added a child to or removed a child (window, other sizer or space) from the sizer while keeping the current dimension.

Types

This = wxSizer()
Window = wxWindow:wxWindow() | wxSizer:wxSizer()
Option =
    {proportion, integer()} |
    {flag, integer()} |
    {border, integer()} |
    {userData, wx:wx_object()}

Same as add/4, but prepends the items to the beginning of the list of items (windows, subsizers or spaces) owned by this sizer.

Types

This = wxSizer()
Option = {prop, integer()}

Prepends stretchable space to the sizer.

More readable way of calling wxSizer::Prepend(0, 0, prop).

Types

This = Sizer = wxSizer()

Removes a sizer child from the sizer and destroys it.

Note: This method does not cause any layout or resizing to take place, call layout/1 to update the layout "on screen" after removing a child from the sizer.

Return: true if the child item was found and removed, false otherwise.

Types

This = wxSizer()
Index = integer()
Newitem = wxSizerItem:wxSizerItem()

Detaches the given item at position index from the sizer and replaces it with the given wxSizerItem newitem.

The detached child is deleted only if it is a sizer or a spacer (but not if it is a wxWindow because windows are owned by their parent window, not the sizer).

This method does not cause any layout or resizing to take place, call layout/1 to update the layout "on screen" after replacing a child from the sizer.

Returns true if the child item was found and removed, false otherwise.

Types

This = wxSizer()
Oldwin = Newwin = wxWindow:wxWindow() | wxSizer:wxSizer()
Option = {recursive, boolean()}

Detaches the given oldwin from the sizer and replaces it with the given newwin.

The detached child window is not deleted (because windows are owned by their parent window, not the sizer).

Use parameter recursive to search the given element recursively in subsizers.

This method does not cause any layout or resizing to take place, call layout/1 to update the layout "on screen" after replacing a child from the sizer.

Returns true if the child item was found and removed, false otherwise.

Types

This = wxSizer()
Pos = {X :: integer(), Y :: integer()}
Size = {W :: integer(), H :: integer()}

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Types

This = wxSizer()
X = Y = Width = Height = integer()

Call this to force the sizer to take the given dimension and thus force the items owned by the sizer to resize themselves according to the rules defined by the parameter in the add/4 and prepend/4 methods.

Types

This = wxSizer()
Size = {W :: integer(), H :: integer()}

Call this to give the sizer a minimal size.

Normally, the sizer will calculate its minimal size based purely on how much space its children need. After calling this method getMinSize/1 will return either the minimal size as requested by its children or the minimal size set here, depending on which is bigger.

Types

This = wxSizer()
Width = Height = integer()

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Types

This = wxSizer()
Window = wxWindow:wxWindow()

This method first calls fit/2 and then setSizeHints/2 on the window passed to it.

This only makes sense when window is actually a wxTopLevelWindow such as a wxFrame or a wxDialog, since SetSizeHints only has any effect in these classes. It does nothing in normal windows or controls.

This method is implicitly used by wxWindow:setSizerAndFit/3 which is commonly invoked in the constructor of a toplevel window itself (see the sample in the description of wxBoxSizer) if the toplevel window is resizable.

Types

This = wxSizer()
Show = boolean()

Show or hide all items managed by the sizer.

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