1wxLayoutAlgorithm(3) Erlang Module Definition wxLayoutAlgorithm(3)
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6 wxLayoutAlgorithm - Functions for wxLayoutAlgorithm class
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9 wxLayoutAlgorithm implements layout of subwindows in MDI or SDI frames.
10 It sends a wxCalculateLayoutEvent (not implemented in wx) event to
11 children of the frame, asking them for information about their size.
12 For MDI parent frames, the algorithm allocates the remaining space to
13 the MDI client window (which contains the MDI child frames).
14 For SDI (normal) frames, a 'main' window is specified as taking up the
16 remaining space.
17 Because the event system is used, this technique can be applied to any
19 windows, which are not necessarily 'aware' of the layout classes (no
20 virtual functions in wxWindow refer to wxLayoutAlgorithm or its
21 events). However, you may wish to use wxSashLayoutWindow for your sub‐
22 windows since this class provides handlers for the required events, and
23 accessors to specify the desired size of the window. The sash behaviour
24 in the base class can be used, optionally, to make the windows user-re‐
25 sizable.
26 wxLayoutAlgorithm is typically used in IDE (integrated development en‐
28 vironment) applications, where there are several resizable windows in
29 addition to the MDI client window, or other primary editing window. Re‐
30 sizable windows might include toolbars, a project window, and a window
31 for displaying error and warning messages.
32 When a window receives an OnCalculateLayout event, it should call Se‐
34 tRect in the given event object, to be the old supplied rectangle minus
35 whatever space the window takes up. It should also set its own size ac‐
36 cordingly. wxSashLayoutWindow::OnCalculateLayout (not implemented in
37 wx) generates an OnQueryLayoutInfo event which it sends to itself to
38 determine the orientation, alignment and size of the window, which it
39 gets from internal member variables set by the application.
40 The algorithm works by starting off with a rectangle equal to the whole
42 frame client area. It iterates through the frame children, generating
43 wxLayoutAlgorithm::OnCalculateLayout events which subtract the window
44 size and return the remaining rectangle for the next window to process.
45 It is assumed (by wxSashLayoutWindow::OnCalculateLayout (not imple‐
46 mented in wx)) that a window stretches the full dimension of the frame
47 client, according to the orientation it specifies. For example, a hori‐
48 zontal window will stretch the full width of the remaining portion of
49 the frame client area. In the other orientation, the window will be
50 fixed to whatever size was specified by wxLayoutAlgorithm::OnQueryLay‐
51 outInfo. An alignment setting will make the window 'stick' to the left,
52 top, right or bottom of the remaining client area. This scheme implies
53 that order of window creation is important. Say you wish to have an ex‐
54 tra toolbar at the top of the frame, a project window to the left of
55 the MDI client window, and an output window above the status bar. You
56 should therefore create the windows in this order: toolbar, output win‐
57 dow, project window. This ensures that the toolbar and output window
58 take up space at the top and bottom, and then the remaining height in-
59 between is used for the project window.
60 wxLayoutAlgorithm is quite independent of the way in which wxLayoutAl‐
62 gorithm::OnCalculateLayout chooses to interpret a window's size and
63 alignment. Therefore you could implement a different window class with
64 a new wxLayoutAlgorithm::OnCalculateLayout event handler, that has a
65 more sophisticated way of laying out the windows. It might allow speci‐
66 fication of whether stretching occurs in the specified orientation, for
67 example, rather than always assuming stretching. (This could, and prob‐
68 ably should, be added to the existing implementation).
69 Note: wxLayoutAlgorithm has nothing to do with wxLayoutConstraints (not
71 implemented in wx). It is an alternative way of specifying layouts for
72 which the normal constraint system is unsuitable.
73 See: wxSashEvent, wxSashLayoutWindow, Overview events
75 wxWidgets docs: wxLayoutAlgorithm
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79 wxLayoutAlgorithm() = wx:wx_object()
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82 new() -> wxLayoutAlgorithm()
83 Default constructor.
85 destroy(This :: wxLayoutAlgorithm()) -> ok
87 Destructor.
89 layoutFrame(This, Frame) -> boolean()
91 Types:
93 This = wxLayoutAlgorithm()
95 Frame = wxFrame:wxFrame()
96 layoutFrame(This, Frame, Options :: [Option]) -> boolean()
98 Types:
100 This = wxLayoutAlgorithm()
102 Frame = wxFrame:wxFrame()
103 Option = {mainWindow, wxWindow:wxWindow()}
104 Lays out the children of a normal frame.
106 mainWindow is set to occupy the remaining space. This function
108 simply calls layoutWindow/3.
109 layoutMDIFrame(This, Frame) -> boolean()
111 Types:
113 This = wxLayoutAlgorithm()
115 Frame = wxMDIParentFrame:wxMDIParentFrame()
116 layoutMDIFrame(This, Frame, Options :: [Option]) -> boolean()
118 Types:
120 This = wxLayoutAlgorithm()
122 Frame = wxMDIParentFrame:wxMDIParentFrame()
123 Option =
124 {rect,
125 {X :: integer(),
126 Y :: integer(),
127 W :: integer(),
128 H :: integer()}}
129 Lays out the children of an MDI parent frame.
131 If rect is non-NULL, the given rectangle will be used as a
133 starting point instead of the frame's client area. The MDI
134 client window is set to occupy the remaining space.
135 layoutWindow(This, Parent) -> boolean()
137 Types:
139 This = wxLayoutAlgorithm()
141 Parent = wxWindow:wxWindow()
142 layoutWindow(This, Parent, Options :: [Option]) -> boolean()
144 Types:
146 This = wxLayoutAlgorithm()
148 Parent = wxWindow:wxWindow()
149 Option = {mainWindow, wxWindow:wxWindow()}
150 Lays out the children of a normal frame or other window.
152 mainWindow is set to occupy the remaining space. If this is not
154 specified, then the last window that responds to a calculate
155 layout event in query mode will get the remaining space (that
156 is, a non-query OnCalculateLayout event will not be sent to this
157 window and the window will be set to the remaining size).
158wxWidgets team. wx 2.3.1 wxLayoutAlgorithm(3)