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 will have to use \helpref{wxBoxSizer}{wxboxsizer},
   5 \helpref{wxStaticBoxSizer}{wxstaticboxsizer} or \helpref{wxNotebookSizer}{wxnotebooksizer}.
   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 initial 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 parameters 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{SetSizeHints}{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 is interpreted relative to the value of other
  79 children of the same wxBoxSizer. For example, you might 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
  84 be combined using the binary OR operator |. Two main behaviours are defined
  85 using these flags. One is the border around a window: the {\it border}
  86 parameter determines the border width whereas the flags given here determine
  87 where the border may be (wxTOP, wxBOTTOM, wxLEFT, wxRIGHT or wxALL). The other
  88 flags determine the child window's behaviour if the size of the sizer changes.
  89 However this is not - in contrast to the {\it option} flag - in the main
  90 orientation, but in the respectively other orientation. So if you created a
  91 wxBoxSizer with the wxVERTICAL option, these flags will be relevant if the
  92 sizer changes its horizontal size. A child may get resized to completely fill
  93 out the new size (using either wxGROW or wxEXPAND), it may get proportionally
  94 resized (wxSHAPED), it may get centered (wxALIGN\_CENTER or wxALIGN\_CENTRE)
  95 or it may get aligned to either side (wxALIGN\_LEFT and wxALIGN\_TOP are set
  96 to 0 and thus represent the default, wxALIGN\_RIGHT and wxALIGN\_BOTTOM have
  97 their obvious meaning). With proportional resize, a child may also be centered
  98 in the main orientation using wxALIGN\_CENTER\_VERTICAL (same as
  99 wxALIGN\_CENTRE\_VERTICAL) and wxALIGN\_CENTER\_HORIZONTAL (same as
 100 wxALIGN\_CENTRE\_HORIZONTAL) flags. Finally, you can also specify
 101 wxADJUST\_MINSIZE flag to make the minimal size of the control dynamically adjust
 102 to the value returned by its \helpref{GetBestSize()}{wxwindowgetbestsize}
 103 method - this allows, for example, for correct relayouting of a static text
 104 control even if its text is changed during run-time.}
 105
 106 \docparam{border}{Determines the border width, if the {\it flag} parameter is set to any border.}
 107
 108 \docparam{userData}{Allows an extra object to be attached to the sizer
 109 item, for use in derived classes when sizing information is more
 110 complex than the {\it option} and {\it flag} will allow for.}
 111
 112 \membersection{wxSizer::CalcMin}\label{wxsizercalcmin}
 113
 114 \func{wxSize}{CalcMin}{\void}
 115
 116 This method is abstract and has to be overwritten by any derived class.
 117 Here, the sizer will do the actual calculation of its children minimal sizes.
 118
 119 \membersection{wxSizer::Fit}\label{wxsizerfit}
 120
 121 \func{void}{Fit}{\param{wxWindow* }{window}}
 122
 123 Tell the sizer to resize the {\it window} to match the sizer's minimal size. This
 124 is commonly done in the constructor of the window itself, see sample in the description
 125 of \helpref{wxBoxSizer}{wxboxsizer}.
 126
 127 \membersection{wxSizer::GetSize}\label{wxsizergetsize}
 128
 129 \func{wxSize}{GetSize}{\void}
 130
 131 Returns the current size of the sizer.
 132
 133 \membersection{wxSizer::GetPosition}\label{wxsizergetposition}
 134
 135 \func{wxPoint}{GetPosition}{\void}
 136
 137 Returns the current position of the sizer.
 138
 139 \membersection{wxSizer::GetMinSize}\label{wxsizergetminsize}
 140
 141 \func{wxSize}{GetMinSize}{\void}
 142
 143 Returns the minimal size of the sizer. This is either the combined minimal
 144 size of all the children and their borders or the minimal size set by
 145 \helpref{SetMinSize}{wxsizersetminsize}, depending on which is bigger.
 146
 147 \membersection{wxSizer::Layout}\label{wxsizerlayout}
 148
 149 \func{void}{Layout}{\void}
 150
 151 Call this to force layout of the children anew, e.g. after having added a child
 152 to or removed a child (window, other sizer or space) from the sizer while keeping
 153 the current dimension.
 154
 155 \membersection{wxSizer::Prepend}\label{wxsizerprepend}
 156
 157 \func{void}{Prepend}{\param{wxWindow* }{window}, \param{int }{option = 0}, \param{int }{flag = 0}, \param{int }{border = 0}, \param{wxObject* }{userData = NULL}}
 158
 159 \func{void}{Prepend}{\param{wxSizer* }{sizer}, \param{int }{option = 0}, \param{int }{flag = 0}, \param{int }{border = 0}, \param{wxObject* }{userData = NULL}}
 160
 161 \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}}
 162
 163 Same as \helpref{wxSizer::Add}{wxsizeradd}, but prepends the items to the beginning of the
 164 list of items (windows, subsizers or spaces) owned by this sizer.
 165
 166 \membersection{wxSizer::RecalcSizes}\label{wxsizerrecalcsizes}
 167
 168 \func{void}{RecalcSizes}{\void}
 169
 170 This method is abstract and has to be overwritten by any derived class.
 171 Here, the sizer will do the actual calculation of its children's positions
 172 and sizes.
 173
 174 \membersection{wxSizer::Remove}\label{wxsizerremove}
 175
 176 \func{bool}{Remove}{\param{wxWindow* }{window}}
 177
 178 \func{bool}{Remove}{\param{wxSizer* }{sizer}}
 179
 180 \func{bool}{Remove}{\param{int }{nth}}
 181
 182 Removes a child from the sizer. {\it window} is the window to be removed, {\it sizer} is the
 183 equivalent sizer and {\it nth} is the position of the child in the sizer, typically 0 for
 184 the first item. This method does not cause any layout or resizing to take place and does
 185 not delete the window itself. Call \helpref{wxSizer::Layout}{wxsizerlayout} to update
 186 the layout "on screen" after removing a child fom the sizer.
 187
 188 Returns TRUE if the child item was found and removed, FALSE otherwise.
 189
 190 \membersection{wxSizer::SetDimension}\label{wxsizersetdimension}
 191
 192 \func{void}{SetDimension}{\param{int }{x}, \param{int }{y}, \param{int }{width}, \param{int }{height}}
 193
 194 Call this to force the sizer to take the given dimension and thus force the items owned
 195 by the sizer to resize themselves according to the rules defined by the paramater in the
 196 \helpref{Add}{wxsizeradd} and \helpref{Prepend}{wxsizerprepend} methods.
 197
 198 \membersection{wxSizer::SetMinSize}\label{wxsizersetminsize}
 199
 200 \func{void}{SetMinSize}{\param{int }{width}, \param{int }{height}}
 201
 202 \func{void}{SetMinSize}{\param{wxSize }{size}}
 203
 204 Call this to give the sizer a minimal size. Normally, the sizer will calculate its
 205 minimal size based purely on how much space its children need. After calling this
 206 method \helpref{GetMinSize}{wxsizergetminsize} will return either the minimal size
 207 as requested by its children or the minimal size set here, depending on which is
 208 bigger.
 209
 210 \membersection{wxSizer::SetItemMinSize}\label{wxsizersetitemminsize}
 211
 212 \func{void}{SetItemMinSize}{\param{wxWindow* }{window}, \param{int}{ width}, \param{int}{ height}}
 213
 214 \func{void}{SetItemMinSize}{\param{wxSizer* }{sizer}, \param{int}{ width}, \param{int}{ height}}
 215
 216 \func{void}{SetItemMinSize}{\param{int}{ pos}, \param{int}{ width}, \param{int}{ height}}
 217
 218 Set an item's minimum size by window, sizer, or position. The item will be found recursively
 219 in the sizer's descendants. This function enables an application to set the size of an item
 220 after initial creation.
 221
 222 \membersection{wxSizer::SetSizeHints}\label{wxsizersetsizehints}
 223
 224 \func{void}{SetSizeHints}{\param{wxWindow* }{window}}
 225
 226 Tell the sizer to set the minimal size of the {\it window} to match the sizer's minimal size.
 227 This is commonly done in the constructor of the window itself, see sample in the description
 228 of \helpref{wxBoxSizer}{wxboxsizer} if the window is resizable (as are many dialogs under Unix and
 229 frames on probably all platforms).
 230