docs/latex/wx/sizer.tex

   1 \section{\class{wxSizer}}\label{wxsizer}
   2
   3 wxSizer is the abstract base class used for laying out subwindows in a window. You
   4 cannot use wxSizer directly; instead, you'll have to use \helpref{wxBoxSizer}{wxboxsizer}
   5 or \helpref{wxStaticBoxSizer}{wxstaticboxsizer}.
   6
   7 The layout algorithm used by sizers in wxWindows is closely related to layout
   8 in other GUI toolkits, such as Java's AWT, the GTK toolkit or the Qt toolkit. It is
   9 based upon the idea of the individual subwindows reporting their minimal required
  10 size and their ability to get stretched if the size of the parent window has changed.
  11 This will most often mean, that the programmer does not set the original size of
  12 a dialog in the beginning, rather the dialog will assigned a sizer and this sizer
  13 will be queried about the recommended size. The sizer in turn will query its
  14 children, which can be normal windows, empty space or other sizers, so that
  15 a hierarchy of sizers can be constructed. Note that wxSizer does not derive from wxWindow
  16 and thus do not interfere with tab ordering and requires very little resources compared
  17 to a real window on screen.
  18
  19 What makes sizers so well fitted for use in wxWindows is the fact that every control
  20 reports its own minimal size and the algorithm can handle differences in font sizes
  21 or different window (dialog item) sizes on different platforms without problems. If e.g.
  22 the standard font as well as the overall design of Motif widgets requires more space than
  23 on Windows, the intial dialog size will automatically be bigger on Motif than on Windows.
  24
  25 \pythonnote{If you wish to create a sizer class in wxPython you should
  26 derive the class from \tt{wxPySizer} in order to get Python-aware
  27 capabilities for the various virtual methods.}
  28
  29 \wxheading{Derived from}
  30
  31 \helpref{wxObject}{wxobject}
  32
  33 \latexignore{\rtfignore{\wxheading{Members}}}
  34
  35 \membersection{wxSizer::wxSizer}\label{wxsizerwxsizer}
  36
  37 \func{}{wxSizer}{\void}
  38
  39 The constructor. Note that wxSizer is an abstract base class and may not
  40 be instantiated.
  41
  42 \membersection{wxSizer::\destruct{wxSizer}}\label{wxsizerdtor}
  43
  44 \func{}{\destruct{wxSizer}}{\void}
  45
  46 The destructor.
  47
  48 \membersection{wxSizer::Add}\label{wxsizeradd}
  49
  50 \func{void}{Add}{\param{wxWindow* }{window}, \param{int }{option = 0},\param{int }{flag = 0}, \param{int }{border = 0}, \param{wxObject* }{userData = NULL}}
  51
  52 \func{void}{Add}{\param{wxSizer* }{sizer}, \param{int }{option = 0}, \param{int }{flag = 0}, \param{int }{border = 0}, \param{wxObject* }{userData = NULL}}
  53
  54 \func{void}{Add}{\param{int }{width}, \param{int }{height}, \param{int }{option = 0}, \param{int }{flag = 0}, \param{int }{border = 0}, \param{wxObject* }{userData = NULL}}
  55
  56 Adds the {\it window} to the sizer. As wxSizer itself is an abstract class, the parameters
  57 have no meaning in the wxSizer class itself, but as there currently is only one class
  58 deriving directly from wxSizer and this class does not override these methods, the meaning
  59 of the paramters is described here:
  60
  61 \docparam{window}{The window to be added to the sizer. Its initial size (either set explicitly by the
  62 user or calculated internally when using wxDefaultSize) is interpreted as the minimal and in many
  63 cases also the initial size. This is particularly useful in connection with \helpref{SetSizeHint}{wxsizersetsizehints}.}
  64
  65 \docparam{sizer}{The (child-)sizer to be added to the sizer. This allows placing a child sizer in a
  66 sizer and thus to create hierarchies of sizers (typically a vertical box as the top sizer and several
  67 horizontal boxes on the level beneath).}
  68
  69 \docparam{width and height}{The dimension of a spacer to be added to the sizer. Adding spacers to sizers
  70 gives more flexilibilty in the design of dialogs; imagine for example a horizontal box with two buttons at the
  71 bottom of a dialog: you might want to insert a space between the two buttons and make that space stretchable
  72 using the {\it option} flag and the result will be that the left button will be aligned with the left
  73 side of the dialog and the right button with the right side - the space in between will shrink and grow with
  74 the dialog.}
  75
  76 \docparam{option}{Although the meaning of this parameter is undefined in wxSizer, it is used in wxBoxSizer
  77 to indicate if a child of a sizer can change its size in the main orientation of the wxBoxSizer - where
  78 0 stands for not changable and a value of more than zero in interpreted relative to the value of other
  79 children of the same wxBoxSizer. You might, e.g., have a horizontal wxBoxSizer with three children, two
  80 of which are supposed to change their size with the sizer, then the two stretchable windows would get a
  81 value of 1 each to make them grow and shrink equally with the sizer's horizontal dimension.}
  82
  83 \docparam{flag}{This parameter can be used to set a number of flags which can be combined using
  84 the binary OR operator |. Two main behaviours are defined using these flags: One is the border
  85 around a window: the {\it border} parameter determines the border width whereas the flags given here
  86 determine where the border may be (wxTOP, wxBOTTOM, wxLEFT, wxRIGHT or wxALL). The other flags
  87 determine the child window's behaviour if the size of the sizer changes, but - in contrast to
  88 the {\it option} flag - not in the main orientation, but the respectively other orientation. So
  89 if you created a wxBoxSizer with the wxVERTICAL option, these flags will be relevant if the
  90 sizer changes its horizontal size. A child may get resized to completely fill out the new size (using
  91 either wxGROW or wxEXPAND), may get proportionally resized (wxSHAPED), may get centered (wxALIGN\_CENTER
  92 or wxALIGN\_CENTRE) or may get aligned to either side (wxALIGN\_LEFT and wxALIGN\_TOP are set to 0
  93 and thus represent the default, wxALIGN\_RIGHT and wxALIGN\_BOTTOM have their obvious meaning).
  94 With proportional resize, a child may also be centered in the main orientation using
  95 wxALIGN\_CENTER\_VERTICAL (same as wxALIGN\_CENTRE\_VERTICAL) and wxALIGN\_CENTER\_HORIZONTAL
  96 (same as wxALIGN\_CENTRE\_HORIZONTAL) flags.}
  97
  98 \docparam{border}{Determines the border width, if the {\it flag} parameter is set to any border.}
  99
 100 \docparam{userData}{Allows an extra object to be attached to the sizer
 101 item, for use in derived classes when sizing information is more
 102 complex than what {\it option} and {\it flag} will allow for.}
 103
 104 \membersection{wxSizer::Prepend}\label{wxsizerprepend}
 105
 106 \func{void}{Prepend}{\param{wxWindow* }{window}, \param{int }{option = 0}, \param{int }{flag = 0}, \param{int }{border = 0}, \param{wxObject* }{userData = NULL}}
 107
 108 \func{void}{Prepend}{\param{wxSizer* }{sizer}, \param{int }{option = 0}, \param{int }{flag = 0}, \param{int }{border = 0}, \param{wxObject* }{userData = NULL}}
 109
 110 \func{void}{Prepend}{\param{int }{width}, \param{int }{height}, \param{int }{option = 0}, \param{int }{flag = 0}, \param{int }{border= 0}, \param{wxObject* }{userData = NULL}}
 111
 112 Same as \helpref{wxSizer::Add}{wxsizeradd}, but prepends the items to the beginning of the
 113 list of items (windows, subsizers or spaces) owned by this sizer.
 114
 115 \membersection{wxSizer::Remove}\label{wxsizerremove}
 116
 117 \func{bool}{Remove}{\param{wxWindow* }{window}}
 118
 119 \func{bool}{Remove}{\param{wxSizer* }{sizer}}
 120
 121 \func{bool}{Remove}{\param{int }{nth}}
 122
 123 Removes a child from the sizer. {\it window} is the window to be removed, {\it sizer} the
 124 equivalent sizer and {\it nth} is the position of the child in the sizer, typically 0 for
 125 the first item. This method does not cause any layout or resizing to take place and does
 126 not delete the window itself. Call \helpref{wxSizer::Layout}{wxsizerlayout} for updating
 127 the layout "on screen" after removing a child fom the sizer.
 128
 129 Returns TRUE if the child item was found and removed, FALSE otherwise.
 130
 131 \membersection{wxSizer::SetDimension}\label{wxsizersetdimension}
 132
 133 \func{void}{SetDimension}{\param{int }{x}, \param{int }{y}, \param{int }{width}, \param{int }{height}}
 134
 135 Call this to force the sizer to take the given dimension and thus force the items owned
 136 by the sizer to resize themselves according to the rules defined by the paramater in the
 137 \helpref{wxSizer::Add}{wxsizeradd} and \helpref{wxSizer::Prepend}{wxsizerprepend} methods.
 138
 139 \membersection{wxSizer::GetSize}\label{wxsizergetsize}
 140
 141 \func{wxSize}{GetSize}{\void}
 142
 143 Returns the current size of the sizer.
 144
 145 \membersection{wxSizer::GetPosition}\label{wxsizergetposition}
 146
 147 \func{wxPoint}{GetPosition}{\void}
 148
 149 Returns the current position of the sizer.
 150
 151 \membersection{wxSizer::GetMinSize}\label{wxsizergetminsize}
 152
 153 \func{wxSize}{GetMinSize}{\void}
 154
 155 Returns the minimal size of the sizer.
 156
 157 \membersection{wxSizer::RecalcSizes}\label{wxsizerrecalcsizes}
 158
 159 \func{void}{RecalcSizes}{\void}
 160
 161 This method is abstract and has to be overwritten by any derived class.
 162 Here, the sizer will do the actual calculation of its children's positions
 163 and sizes.
 164
 165 \membersection{wxSizer::CalcMin}\label{wxsizercalcmin}
 166
 167 \func{wxSize}{CalcMin}{\void}
 168
 169 This method is abstract and has to be overwritten by any derived class.
 170 Here, the sizer will do the actual calculation of its children minimal sizes.
 171
 172 \membersection{wxSizer::Layout}\label{wxsizerlayout}
 173
 174 \func{void}{Layout}{\void}
 175
 176 Call this to force laying out the children anew, e.g. after having added a child
 177 to or removed a child (window, other sizer or space) from the sizer while keeping
 178 the current dimension.
 179
 180 \membersection{wxSizer::Fit}\label{wxsizerfit}
 181
 182 \func{void}{Fit}{\param{wxWindow* }{window}}
 183
 184 Tell the sizer to resize the {\it window} to match the sizer's minimal size. This
 185 is commonly done in the constructor of the window itself, see sample in the description
 186 of \helpref{wxBoxSizer}{wxboxsizer}.
 187
 188 \membersection{wxSizer::SetSizeHints}\label{wxsizersetsizehints}
 189
 190 \func{void}{SetSizeHints}{\param{wxWindow* }{window}}
 191
 192 Tell the sizer to set the minimal size of the {\it window} to match the sizer's minimal size.
 193 This is commonly done in the constructor of the window itself, see sample in the description
 194 of \helpref{wxBoxSizer}{wxboxsizer} if the window is resizable (as many dialogs under Unix and
 195 frames on probably all platforms).
 196