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 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. However this is not - in contrast to
  88 the {\it option} flag - in the main orientation, but in 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), it may get proportionally resized (wxSHAPED), it may get centered (wxALIGN\_CENTER
  92 or wxALIGN\_CENTRE) or it 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 the {\it option} and {\it flag} will allow for.}
 103
 104 \membersection{wxSizer::CalcMin}\label{wxsizercalcmin}
 105
 106 \func{wxSize}{CalcMin}{\void}
 107
 108 This method is abstract and has to be overwritten by any derived class.
 109 Here, the sizer will do the actual calculation of its children minimal sizes.
 110
 111 \membersection{wxSizer::Fit}\label{wxsizerfit}
 112
 113 \func{void}{Fit}{\param{wxWindow* }{window}}
 114
 115 Tell the sizer to resize the {\it window} to match the sizer's minimal size. This
 116 is commonly done in the constructor of the window itself, see sample in the description
 117 of \helpref{wxBoxSizer}{wxboxsizer}.
 118
 119 \membersection{wxSizer::GetSize}\label{wxsizergetsize}
 120
 121 \func{wxSize}{GetSize}{\void}
 122
 123 Returns the current size of the sizer.
 124
 125 \membersection{wxSizer::GetPosition}\label{wxsizergetposition}
 126
 127 \func{wxPoint}{GetPosition}{\void}
 128
 129 Returns the current position of the sizer.
 130
 131 \membersection{wxSizer::GetMinSize}\label{wxsizergetminsize}
 132
 133 \func{wxSize}{GetMinSize}{\void}
 134
 135 Returns the minimal size of the sizer. This is either the combined minimal
 136 size of all the children and their borders or the minimal size set by
 137 \helpref{SetMinSize}{wxsizersetminsize}, depending on which is bigger.
 138
 139 \membersection{wxSizer::Layout}\label{wxsizerlayout}
 140
 141 \func{void}{Layout}{\void}
 142
 143 Call this to force layout of the children anew, e.g. after having added a child
 144 to or removed a child (window, other sizer or space) from the sizer while keeping
 145 the current dimension.
 146
 147 \membersection{wxSizer::Prepend}\label{wxsizerprepend}
 148
 149 \func{void}{Prepend}{\param{wxWindow* }{window}, \param{int }{option = 0}, \param{int }{flag = 0}, \param{int }{border = 0}, \param{wxObject* }{userData = NULL}}
 150
 151 \func{void}{Prepend}{\param{wxSizer* }{sizer}, \param{int }{option = 0}, \param{int }{flag = 0}, \param{int }{border = 0}, \param{wxObject* }{userData = NULL}}
 152
 153 \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}}
 154
 155 Same as \helpref{wxSizer::Add}{wxsizeradd}, but prepends the items to the beginning of the
 156 list of items (windows, subsizers or spaces) owned by this sizer.
 157
 158 \membersection{wxSizer::RecalcSizes}\label{wxsizerrecalcsizes}
 159
 160 \func{void}{RecalcSizes}{\void}
 161
 162 This method is abstract and has to be overwritten by any derived class.
 163 Here, the sizer will do the actual calculation of its children's positions
 164 and sizes.
 165
 166 \membersection{wxSizer::Remove}\label{wxsizerremove}
 167
 168 \func{bool}{Remove}{\param{wxWindow* }{window}}
 169
 170 \func{bool}{Remove}{\param{wxSizer* }{sizer}}
 171
 172 \func{bool}{Remove}{\param{int }{nth}}
 173
 174 Removes a child from the sizer. {\it window} is the window to be removed, {\it sizer} is the
 175 equivalent sizer and {\it nth} is the position of the child in the sizer, typically 0 for
 176 the first item. This method does not cause any layout or resizing to take place and does
 177 not delete the window itself. Call \helpref{wxSizer::Layout}{wxsizerlayout} to update
 178 the layout "on screen" after removing a child fom the sizer.
 179
 180 Returns TRUE if the child item was found and removed, FALSE otherwise.
 181
 182 \membersection{wxSizer::SetDimension}\label{wxsizersetdimension}
 183
 184 \func{void}{SetDimension}{\param{int }{x}, \param{int }{y}, \param{int }{width}, \param{int }{height}}
 185
 186 Call this to force the sizer to take the given dimension and thus force the items owned
 187 by the sizer to resize themselves according to the rules defined by the paramater in the
 188 \helpref{Add}{wxsizeradd} and \helpref{Prepend}{wxsizerprepend} methods.
 189
 190 \membersection{wxSizer::SetMinSize}\label{wxsizersetminsize}
 191
 192 \func{void}{SetMinSize}{\param{int }{width}, \param{int }{height}}
 193
 194 \func{void}{SetMinSize}{\param{wxSize }{size}}
 195
 196 Call this to give the sizer a minimal size. Normally, the sizer will calculate its
 197 minimal size based purely on how much space its children need. After calling this
 198 method \helpref{GetMinSize}{wxsizergetminsize} will return either the minimal size
 199 as requested by its children or the minimal size set here, depending on which is
 200 bigger.
 201
 202 \membersection{wxSizer::SetItemMinSize}\label{wxsizersetitemminsize}
 203
 204 \func{void}{SetItemMinSize}{\param{wxWindow* }{window}, \param{int}{ width}, \param{int}{ height}}
 205
 206 \func{void}{SetItemMinSize}{\param{wxSizer* }{sizer}, \param{int}{ width}, \param{int}{ height}}
 207
 208 \func{void}{SetItemMinSize}{\param{int}{ pos}, \param{int}{ width}, \param{int}{ height}}
 209
 210 Set an item's minimum size by window, sizer, or position. The item will be found recursively
 211 in the sizer's descendants. This function enables an application to set the size of an item
 212 after initial creation.
 213
 214 \membersection{wxSizer::SetSizeHints}\label{wxsizersetsizehints}
 215
 216 \func{void}{SetSizeHints}{\param{wxWindow* }{window}}
 217
 218 Tell the sizer to set the minimal size of the {\it window} to match the sizer's minimal size.
 219 This is commonly done in the constructor of the window itself, see sample in the description
 220 of \helpref{wxBoxSizer}{wxboxsizer} if the window is resizable (as are many dialogs under Unix and
 221 frames on probably all platforms).
 222