From d13c96bbf91d9f8b261d2ccf29e605e4aa6509b5 Mon Sep 17 00:00:00 2001 From: Robin Dunn Date: Sun, 29 May 2016 20:20:41 -0700 Subject: [PATCH] Update sizers overview --- .../overviews/sizers_overview.rst | 607 ++++++++++-------- 1 file changed, 333 insertions(+), 274 deletions(-) diff --git a/docs/sphinx/rest_substitutions/overviews/sizers_overview.rst b/docs/sphinx/rest_substitutions/overviews/sizers_overview.rst index 3a42de3c..9e842596 100644 --- a/docs/sphinx/rest_substitutions/overviews/sizers_overview.rst +++ b/docs/sphinx/rest_substitutions/overviews/sizers_overview.rst @@ -8,50 +8,73 @@ ============================================= -Sizers, as represented by the :ref:`Sizer` class and its descendants in the wxPython class hierarchy, have become the method of -choice to define the layout of controls in dialogs in wxPython because of their ability to create visually appealing dialogs -independent of the platform, taking into account the differences in size and style of the individual controls. -Editors such as wxDesigner, DialogBlocks, XRCed and wxWorkshop create dialogs based exclusively on sizers, practically forcing -the user to create platform independent layouts without compromises. +Sizers, as represented by the :ref:`wx.Sizer` class and its +descendants in the wxPython class hierarchy, have become the method of +choice to define the layout of controls in dialogs in wxPython because +of their ability to create visually appealing dialogs independent of +the platform, taking into account the differences in size and style of +the individual controls. Editors such as wxDesigner, DialogBlocks, +XRCed and wxWorkshop create dialogs based exclusively on sizers, +practically forcing the user to create platform independent layouts +without compromises. -The next section describes and shows what can be done with sizers. The following sections briefly describe how to program with -individual sizer classes. +The next section describes and shows what can be done with sizers. The +following sections briefly describe how to program with individual +sizer classes. The Idea Behind Sizers ---------------------- -The layout algorithm used by sizers in wxPython is closely related to layout systems in other GUI toolkits, such as Java's AWT, -the GTK toolkit or the Qt toolkit. It is based upon the idea of 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 start-up size of a dialog, the dialog will rather be assigned a sizer and this sizer will be queried about the -recommended size. This 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 :ref:`Sizer` does not derive from :ref:`Window` and thus does not -interfere with tab ordering and requires very few resources compared to a real window on screen. +The layout algorithm used by sizers in wxPython is closely related to +layout systems in other GUI toolkits, such as Java's AWT, the GTK +toolkit or the Qt toolkit. It is based upon the idea of 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 start-up size of +a dialog, the dialog will rather be assigned a sizer and this sizer +will be queried about the recommended size. This 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 +:ref:`wx.Sizer` does not derive from :ref:`wx.Window` and thus does +not interfere with tab ordering and requires very few resources +compared to a real window on screen. -What makes sizers so well fitted for use in wxPython 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. For example, -if the standard font as well as the overall design of Linux/GTK widgets requires more space than on Windows, the initial dialog -size will automatically be bigger on Linux/GTK than on Windows. +What makes sizers so well fitted for use in wxPython 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. For example, if the +standard font as well as the overall design of Linux/GTK widgets +requires more space than on Windows, the initial dialog size will +automatically be bigger on Linux/GTK than on Windows. -There are currently five different kinds of sizers available in wxPython. Each represents either a certain way to lay out dialog -items in a dialog or it fulfills a special task such as wrapping a static box around a dialog item (or another sizer). These sizers -will be discussed one by one in the text below. For more detailed information on how to use sizers programmatically, please refer -to the section :ref:`Programming with BoxSizer `. +There are currently five different kinds of sizers available in +wxPython. Each represents either a certain way to lay out dialog items +in a dialog or it fulfills a special task such as wrapping a static +box around a dialog item (or another sizer). These sizers will be +discussed one by one in the text below. For more detailed information +on how to use sizers programmatically, please refer to the section +:ref:`Programming with BoxSizer `. Common Features --------------- -All sizers are containers, that is, they are used to lay out one dialog item (or several dialog items), which they contain. Such -items are sometimes referred to as the children of the sizer. Independent of how the individual sizers lay out their children, -all children have certain features in common: +All sizers are containers, that is, they are used to lay out one +dialog item (or several dialog items), which they contain. Such items +are sometimes referred to as the children of the sizer. Independent of +how the individual sizers lay out their children, all children have +certain features in common: -**A minimal size**: This minimal size is usually identical to the initial size of the controls and may either be set explicitly in -the :ref:`Size` field of the control constructor or may be calculated by wxPython, typically by setting the height and/or the width -of the item to -1. Note that only some controls can calculate their size (such as a checkbox) whereas others (such as a listbox) -don't have any natural width or height and thus require an explicit size. Some controls can calculate their height, but not their -width (e.g. a single line text control): +**A minimal size**: This minimal size is usually identical to the +initial size of the controls and may either be set explicitly in the +:ref:`wx.Size` field of the control constructor or may be calculated +by wxPython, typically by setting the height and/or the width of the +item to -1. Note that only some controls can calculate their size +(such as a checkbox) whereas others (such as a listbox) don't have any +natural width or height and thus require an explicit size. Some +controls can calculate their height, but not their width (e.g. a +single line text control): .. figure:: _static/images/overviews/overview_sizer_04.png @@ -61,9 +84,12 @@ width (e.g. a single line text control): | -**A border**: The border is just empty space and is used to separate dialog items in a dialog. This border can either be all around, -or at any combination of sides such as only above and below the control. The thickness of this border must be set explicitly, typically -5 points. The following samples show dialogs with only one dialog item (a button) and a border of 0, 5, and 10 pixels around the button: +**A border**: The border is just empty space and is used to separate +dialog items in a dialog. This border can either be all around, or at +any combination of sides such as only above and below the control. The +thickness of this border must be set explicitly, typically 5 +points. The following samples show dialogs with only one dialog item +(a button) and a border of 0, 5, and 10 pixels around the button: .. figure:: _static/images/overviews/overview_sizer_02.png @@ -73,11 +99,15 @@ or at any combination of sides such as only above and below the control. The thi | -**An alignment**: Often, a dialog item is given more space than its minimal size plus its border. Depending on what flags are used -for the respective dialog item, the dialog item can be made to fill out the available space entirely, i.e. it will grow to a size -larger than the minimal size, or it will be moved to either the centre of the available space or to either side of the space. The -following sample shows a listbox and three buttons in a horizontal box sizer; one button is centred, one is aligned at the top, one is -aligned at the bottom: +**An alignment**: Often, a dialog item is given more space than its +minimal size plus its border. Depending on what flags are used for the +respective dialog item, the dialog item can be made to fill out the +available space entirely, i.e. it will grow to a size larger than the +minimal size, or it will be moved to either the centre of the +available space or to either side of the space. The following sample +shows a listbox and three buttons in a horizontal box sizer; one +button is centred, one is aligned at the top, one is aligned at the +bottom: .. figure:: _static/images/overviews/overview_sizer_06.png @@ -87,13 +117,20 @@ aligned at the bottom: | -**A stretch factor**: If a sizer contains more than one child and it is offered more space than its children and their borders need, the -question arises how to distribute the surplus space among the children. For this purpose, a stretch factor may be assigned to each child, -where the default value of 0 indicates that the child will not get more space than its requested minimum size. A value of more than zero -is interpreted in relation to the sum of all stretch factors in the children of the respective sizer, i.e. if two children get a stretch -factor of 1, they will get half the extra space each independent of whether one control has a minimal sizer inferior to the other or not. -The following sample shows a dialog with three buttons, the first one has a stretch factor of 1 and thus gets stretched, whereas the other -two buttons have a stretch factor of zero and keep their initial width: +**A stretch factor**: If a sizer contains more than one child and it +is offered more space than its children and their borders need, the +question arises how to distribute the surplus space among the +children. For this purpose, a stretch factor may be assigned to each +child, where the default value of 0 indicates that the child will not +get more space than its requested minimum size. A value of more than +zero is interpreted in relation to the sum of all stretch factors in +the children of the respective sizer, i.e. if two children get a +stretch factor of 1, they will get half the extra space each +independent of whether one control has a minimal sizer inferior to the +other or not. The following sample shows a dialog with three buttons, +the first one has a stretch factor of 1 and thus gets stretched, +whereas the other two buttons have a stretch factor of zero and keep +their initial width: .. figure:: _static/images/overviews/overview_sizer_07.png @@ -103,7 +140,8 @@ two buttons have a stretch factor of zero and keep their initial width: | -Within wxDesigner, this stretch factor gets set from the `Option` menu. +Within wxDesigner, this stretch factor gets set from the `Option` +menu. `wx.Sizers` - the visual approach @@ -114,25 +152,21 @@ Within wxDesigner, this stretch factor gets set from the `Option` menu. Basic way of adding a window ---------------------------- -Let's take a look at :class:`BoxSizer`. -This is the most simple type of box sizer, and the way we add widgets to it is explained by looking -at the :meth:`BoxSizer.Add` signature: +Let's take a look at :class:`wx.BoxSizer`. This is the most simple +type of box sizer, and the way we add widgets to it is explained by +looking at the :meth:`wx.BoxSizer.Add` signature: -.. raw:: html - -
- -.. method:: Add(window, proportion=0, flag=0, border=0, userData=None) +.. function:: Add(window, proportion=0, flag=0, border=0, userData=None) Appends a child to the sizer. :param `window`: a window, a spacer or another sizer to be added to the sizer. Its initial size (either set explicitly by the user or calculated internally) is interpreted as the minimal and in many cases also the initial size. - :param int proportion: this parameter is used in :class:`BoxSizer` to indicate if a child of a sizer - can change its size in the main orientation of the :class:`BoxSizer` - where 0 stands for not changeable + :param int proportion: this parameter is used in :class:`wx.BoxSizer` to indicate if a child of a sizer + can change its size in the main orientation of the :class:`wx.BoxSizer` - where 0 stands for not changeable and a value of more than zero is interpreted relative to the value of other children of the same - :class:`BoxSizer`. For example, you might have a horizontal :class:`BoxSizer` with three children, two + :class:`wx.BoxSizer`. For example, you might have a horizontal :class:`wx.BoxSizer` with three children, two of which are supposed to change their size with the sizer. Then the two stretchable windows would get a value of 1 each to make them grow and shrink equally with the sizer's horizontal dimension. :param int flag: OR-combination of flags affecting sizer's behaviour. @@ -140,15 +174,13 @@ at the :meth:`BoxSizer.Add` signature: :param object userData: allows an extra object to be attached to the sizer item, for use in derived classes when sizing information is more complex than the proportion and flag will allow for. - :rtype: :class:`SizerItem` - -.. raw:: html - -
+ :rtype: :class:`wx.SizerItem` -Let's create a vertical sizer (children will be placed on top of each other) and place two buttons in it. -All the "extra" parameters are set to 0; we'll worry about them later. + +Let's create a vertical sizer (children will be placed on top of each +other) and place two buttons in it. All the "extra" parameters are +set to 0; we'll worry about them later. .. figure:: _static/images/overviews/boxsizer1.png :class: floatright @@ -163,9 +195,12 @@ All the "extra" parameters are set to 0; we'll worry about them later. You'll notice a couple of things about this: -* The buttons are just big enough to accommodate the text in them. In fact, any control placed - into a sizer this way will appear at its minimum size unless we change the parameters. -* The window size is not changed to fit the sizer. This results in a lot of ugly empty space. +* The buttons are just big enough to accommodate the text in them. In + fact, any control placed into a sizer this way will appear at its + minimum size unless we change the parameters. + +* The window size is not changed to fit the sizer. This results in a + lot of ugly empty space. Let's worry about the second issue first. To make the window size more appropriate, we can set @@ -183,17 +218,20 @@ the size hints to tell the enclosing window to adjust to the size of the sizer: sizer.SetSizeHints(self) self.SetSizer(sizer) -This is particularly useful in circumstances like this one, in which the :class:`Frame`'s default size -would otherwise be much too big or small to show most layouts in an aesthetically pleasing manner. +This is particularly useful in circumstances like this one, in which +the :class:`wx.Frame`\ 's default size would otherwise be much too big +or small to show most layouts in an aesthetically pleasing manner. -------------------------- The `proportion` parameter -------------------------- -The first parameter to :meth:`BoxSizer.Add` -is obviously the :class:`Window` or :class:`Sizer` that you are adding. The second one (the `proportion`) -defines how large the sizer's children are in relation to each other. In a vertical sizer, this changes -the height; in a horizontal sizer, this changes the width. Here are some examples: +The first parameter to :meth:`wx.BoxSizer.Add` is obviously the +:class:`wx.Window` or :class:`wx.Sizer` that you are adding. The +second one (the `proportion`) defines how large the sizer's children +are in relation to each other. In a vertical sizer, this changes the +height; in a horizontal sizer, this changes the width. Here are some +examples: .. list-table:: :header-rows: 1 @@ -207,17 +245,18 @@ the height; in a horizontal sizer, this changes the width. Here are some example * - .. code-block:: python :emphasize-lines: 3,4 - sizer = wx.BoxSizer(wx.VERTICAL) - # Second button is three times as tall as first button - sizer.Add(wx.Button(self, -1, 'An extremely long button text'), 1, 0, 0) - sizer.Add(wx.Button(self, -1, 'Small button'), 3, 0, 0) - sizer.SetSizeHints(self) - self.SetSizer(sizer) + sizer = wx.BoxSizer(wx.VERTICAL) + # Second button is three times as tall as first button + sizer.Add(wx.Button(self, -1, 'An extremely long button text'), 1, 0, 0) + sizer.Add(wx.Button(self, -1, 'Small button'), 3, 0, 0) + sizer.SetSizeHints(self) + self.SetSizer(sizer) - .. figure:: _static/images/overviews/boxsizer3.png :align: left - * - Same code as above, with window resized. Notice that the bottom button is still three times as tall as the top button. + * - Same code as above, with window resized. Notice that the bottom + button is still three times as tall as the top button. - .. figure:: _static/images/overviews/boxsizer31.png :align: left @@ -234,12 +273,12 @@ the height; in a horizontal sizer, this changes the width. Here are some example - .. figure:: _static/images/overviews/boxsizer32.png :align: left - + | -If one of the `proportion` parameters is 0, that :class:`Window` will be the minimum size, and the others -will resize proportionally: +If one of the `proportion` parameters is 0, that :class:`wx.Window` +will be the minimum size, and the others will resize proportionally: .. list-table:: :header-rows: 1 @@ -271,69 +310,33 @@ will resize proportionally: :align: left -This is especially useful when you want, for example, a button at the bottom which is only -as big as necessary, and some other control that occupies the rest of the frame. To do so, -give the button proportion 0 and the other control a number greater than 0. Mac users in -particular will appreciate you for not creating huge aqua-styled buttons. +This is especially useful when you want, for example, a button at the +bottom which is only as big as necessary, and some other control that +occupies the rest of the frame. To do so, give the button proportion 0 +and the other control a number greater than 0. Mac users in particular +will appreciate you for not creating huge aqua-styled buttons. ----------------------------------- The `flags` and `border` parameters ----------------------------------- -The `flag` argument accepted by :meth:`Sizer.Add` -is a ``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. +The `flag` argument accepted by :meth:`wx.Sizer.Add` is a +``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. -+---------------------------------------------------------------------+-----------------------------------------------------------------------------+ -| Sizer Flag | Description | -+=====================================================================+=============================================================================+ -| ``TOP`` | These flags are used to specify which side(s) of the sizer | -+---------------------------------------------------------------------+ item the border width will apply to. | -| ``BOTTOM`` | | -+---------------------------------------------------------------------+ | -| ``LEFT`` | | -+---------------------------------------------------------------------+ | -| ``RIGHT`` | | -+---------------------------------------------------------------------+ | -| ``ALL`` | | -+---------------------------------------------------------------------+-----------------------------------------------------------------------------+ -| ``EXPAND`` | The item will be expanded to fill the space assigned to | -| | the item. | -+---------------------------------------------------------------------+-----------------------------------------------------------------------------+ -| ``SHAPED`` | The item will be expanded as much as possible while also | -| | maintaining its aspect ratio | -+---------------------------------------------------------------------+-----------------------------------------------------------------------------+ -| ``FIXED_MINSIZE`` | If you would rather have a window item stay the size it started with then | -| | use ``FIXED_MINSIZE`` | -+---------------------------------------------------------------------+-----------------------------------------------------------------------------+ -| ``RESERVE_SPACE_EVEN_IF_HIDDEN`` | Normally `Sizers` don't allocate space for hidden windows or other items. | -| | This flag overrides this behavior so that sufficient space is allocated for | -| | the window even if it isn't visible. This makes it possible to dynamically | -| | show and hide controls without resizing parent dialog, for example. | -+---------------------------------------------------------------------+-----------------------------------------------------------------------------+ -| ``ALIGN_CENTER`` **or** ``ALIGN_CENTRE`` | The ``ALIGN*`` flags allow you to specify the alignment of the item | -+---------------------------------------------------------------------+ within the space allotted to it by the sizer, adjusted for the border if | -| ``ALIGN_LEFT`` | any. | -+---------------------------------------------------------------------+ | -| ``ALIGN_RIGHT`` | | -+---------------------------------------------------------------------+ | -| ``ALIGN_TOP`` | | -+---------------------------------------------------------------------+ | -| ``ALIGN_BOTTOM`` | | -+---------------------------------------------------------------------+ | -| ``ALIGN_CENTER_VERTICAL`` **or** ``ALIGN_CENTRE_VERTICAL`` | | -+---------------------------------------------------------------------+ | -| ``ALIGN_CENTER_HORIZONTAL`` **or** ``ALIGN_CENTRE_HORIZONTAL`` | | -+---------------------------------------------------------------------+-----------------------------------------------------------------------------+ +.. include:: rest_substitutions/tables/wx.Sizer.1.rst | -Let's start with the simplest case: the alignment flags. These are pretty self-explanatory. +Let's start with the simplest case: the alignment flags. These are +pretty self-explanatory. .. list-table:: :header-rows: 1 @@ -375,7 +378,7 @@ Let's start with the simplest case: the alignment flags. These are pretty self-e -Next is the ``EXPAND`` flag. This is synonymous with ``GROW``. +Next is the ``wx.EXPAND`` flag. This is synonymous with ``wx.GROW``. .. list-table:: :header-rows: 1 @@ -403,10 +406,10 @@ Next is the ``EXPAND`` flag. This is synonymous with ``GROW``. You can see that the first button takes its minimum size, and the second one grows to match it. This affects -controls in the opposite manner of the second parameter; ``EXPAND`` in a vertical sizer causes horizontal +controls in the opposite manner of the second parameter; ``wx.EXPAND`` in a vertical sizer causes horizontal expansion, and in a horizontal sizer it causes vertical expansion. -Next is ``SHAPED``. This flag ensures that the width and height of the object stay proportional to each other. +Next is ``wx.SHAPED``. This flag ensures that the width and height of the object stay proportional to each other. It doesn't make much sense for buttons, but can be excellent for bitmaps, which would be contorted or clipped if not scaled proportionally. @@ -434,16 +437,19 @@ if not scaled proportionally. - .. figure:: _static/images/overviews/boxsizer51.png :align: left - * - Same code as above, with window resized. The width grew dramatically with the height. In fact, it didn't - quite grow vertically the whole way because it couldn't maintain the correct ratio while doing so. + * - Same code as above, with window resized. The width grew + dramatically with the height. In fact, it didn't quite grow + vertically the whole way because it couldn't maintain the + correct ratio while doing so. - .. figure:: _static/images/overviews/boxsizer52.png :align: left -Finally, we have the border flags. These only make sense when the `border` parameter is greater than 0, and describe -the sides of the control on which the border should appear. In order to demonstrate this most clearly, we'll keep -the ``EXPAND`` flag. +Finally, we have the border flags. These only make sense when the +`border` parameter is greater than 0, and describe the sides of the +control on which the border should appear. In order to demonstrate +this most clearly, we'll keep the ``wx.EXPAND`` flag. .. list-table:: @@ -514,31 +520,42 @@ the ``EXPAND`` flag. :align: left -You can see that the button is offset from the specified edges of the sizer by the number of pixels that we -specified in the `border` parameter. +You can see that the button is offset from the specified edges of the +sizer by the number of pixels that we specified in the `border` +parameter. Hiding Controls Using Sizers ---------------------------- -You can hide controls contained in sizers the same way you would hide any control, using the :meth:`Window.Show` method. However, :ref:`Sizer` -also offers a separate method which can tell the sizer not to consider that control in its size calculations. To hide a window using the -sizer, call :meth:`Sizer.Show`. You must then call `Layout` on the sizer to force an update. +You can hide controls contained in sizers the same way you would hide +any control, using the :meth:`wx.Window.Show` method. However, +:ref:`wx.Sizer` also offers a separate method which can tell the sizer +not to consider that control in its size calculations. To hide a +window using the sizer, call :meth:`wx.Sizer.Show`. You must then call +`Layout` on the sizer to force an update. -This is useful when hiding parts of the interface, since you can avoid removing the controls from the sizer and having to add them back later. +This is useful when hiding parts of the interface, since you can avoid +removing the controls from the sizer and having to add them back +later. -.. note:: This is supported only by :ref:`BoxSizer` and :ref:`FlexGridSizer`. +.. note:: This is supported only by :ref:`wx.BoxSizer` and :ref:`wx.FlexGridSizer`. -------- BoxSizer -------- -:ref:`BoxSizer` can lay out its children either vertically or horizontally, depending on what flag is being used in its constructor. -When using a vertical sizer, each child can be centered, aligned to the right or aligned to the left. Correspondingly, when using a -horizontal sizer, each child can be centered, aligned at the bottom or aligned at the top. The stretch factor described in the last -paragraph is used for the main orientation, i.e. when using a horizontal box sizer, the stretch factor determines how much the child can -be stretched horizontally. The following sample shows the same dialog as in the last sample, only the box sizer is a vertical box sizer now: +:ref:`wx.BoxSizer` can lay out its children either vertically or +horizontally, depending on what flag is being used in its constructor. +When using a vertical sizer, each child can be centered, aligned to +the right or aligned to the left. Correspondingly, when using a +horizontal sizer, each child can be centered, aligned at the bottom or +aligned at the top. The stretch factor described in the last paragraph +is used for the main orientation, i.e. when using a horizontal box +sizer, the stretch factor determines how much the child can be +stretched horizontally. The following sample shows the same dialog as +in the last sample, only the box sizer is a vertical box sizer now: .. figure:: _static/images/overviews/overview_sizer_08.png :align: center @@ -548,7 +565,8 @@ be stretched horizontally. The following sample shows the same dialog as in the StaticBoxSizer -------------- -:class:`StaticBoxSixer` is the same as a :class:`BoxSizer`, but surrounded by a static box. Here is a sample: +:class:`wx.StaticBoxSixer` is the same as a :class:`wx.BoxSizer`, but +surrounded by a static box. Here is a sample: .. figure:: _static/images/overviews/overview_sizer_09.png @@ -559,25 +577,31 @@ StaticBoxSizer GridSizer --------- -:ref:`GridSizer` is a two-dimensional sizer. All children are given the same size, which is the minimal size required by the biggest -child, in this case the text control in the left bottom border. Either the number of columns or the number or rows is fixed and the grid -sizer will grow in the respectively other orientation if new children are added: +:ref:`wx.GridSizer` is a two-dimensional sizer. All children are given +the same size, which is the minimal size required by the biggest +child, in this case the text control in the left bottom border. Either +the number of columns or the number or rows is fixed and the grid +sizer will grow in the respectively other orientation if new children +are added: .. figure:: _static/images/overviews/overview_sizer_10.png :align: center -For programming information, see :ref:`GridSizer`. +For programming information, see :ref:`wx.GridSizer`. ------------- FlexGridSizer ------------- -Another two-dimensional sizer derived from :ref:`GridSizer`. The width of each column and the height of each row are calculated individually -according to the minimal requirements from the respectively biggest child. Additionally, columns and rows can be declared to be stretchable -if the sizer is assigned a size different from the one it requested. The following sample shows the same dialog as the one above, but using -a flex grid sizer: +Another two-dimensional sizer derived from :ref:`wx.GridSizer`. The +width of each column and the height of each row are calculated +individually according to the minimal requirements from the +respectively biggest child. Additionally, columns and rows can be +declared to be stretchable if the sizer is assigned a size different +from the one it requested. The following sample shows the same dialog +as the one above, but using a flex grid sizer: .. figure:: _static/images/overviews/overview_sizer_11.png @@ -590,154 +614,189 @@ a flex grid sizer: Programming with BoxSizer --------------------------- -The basic idea behind a :ref:`BoxSizer` is that windows will most often be laid out in rather simple basic geometry, typically in a row or a -column or several hierarchies of either. +The basic idea behind a :ref:`wx.BoxSizer` is that windows will most +often be laid out in rather simple basic geometry, typically in a row +or a column or several hierarchies of either. -As an example, we will construct a dialog that will contain a text field at the top and two buttons at the bottom. This can be seen as a -top-hierarchy column with the text at the top and buttons at the bottom and a low-hierarchy row with an ``OK`` button to the left and a ``Cancel`` -button to the right. In many cases (particularly dialogs under Unix and normal frames) the main window will be resizable by the user and this -change of size will have to get propagated to its children. In our case, we want the text area to grow with the dialog, whereas the button -shall have a fixed size. In addition, there will be a thin border around all controls to make the dialog look nice and - to make matter worse - the -buttons shall be centred as the width of the dialog changes. +As an example, we will construct a dialog that will contain a text +field at the top and two buttons at the bottom. This can be seen as a +top-hierarchy column with the text at the top and buttons at the +bottom and a low-hierarchy row with an ``OK`` button to the left and a +``Cancel`` button to the right. In many cases (particularly dialogs +under Unix and normal frames) the main window will be resizable by the +user and this change of size will have to get propagated to its +children. In our case, we want the text area to grow with the dialog, +whereas the button shall have a fixed size. In addition, there will be +a thin border around all controls to make the dialog look nice and - +to make matter worse - the buttons shall be centred as the width of +the dialog changes. -It is the unique feature of a box sizer, that it can grow in both directions (height and width) but can distribute its growth in the -main direction (horizontal for a row) `unevenly` among its children. In our example case, the vertical sizer is supposed to propagate all its -height changes to only the text area, not to the button area. This is determined by the `proportion` parameter when adding a window (or -another sizer) to a sizer. It is interpreted as a weight factor, i.e. it can be zero, indicating that the window may not be resized at all, -or above zero. If several windows have a value above zero, the value is interpreted relative to the sum of all weight factors of the sizer, -so when adding two windows with a value of 1, they will both get resized equally much and each half as much as the sizer owning them. -Then what do we do when a column sizer changes its width? This behaviour is controlled by `flags` (the second parameter of the `Add()` function): -Zero or no flag indicates that the window will preserve it is original size, ``GROW`` flag (same as ``EXPAND``) forces the window to grow with -the sizer, and ``SHAPED`` flag tells the window to change it is size proportionally, preserving original aspect ratio. When ``GROW`` flag is -not used, the item can be aligned within available space. ``ALIGN_LEFT``, ``ALIGN_TOP``, ``ALIGN_RIGHT``, ``ALIGN_BOTTOM``, ``ALIGN_CENTER_HORIZONTAL`` -and ``ALIGN_CENTER_VERTICAL`` do what they say. ``ALIGN_CENTRE`` (same as ``ALIGN_CENTER``) is defined as -(``ALIGN_CENTER_HORIZONTAL`` | ``ALIGN_CENTER_VERTICAL``). Default alignment is ``ALIGN_LEFT`` | ``ALIGN_TOP``. +It is the unique feature of a box sizer, that it can grow in both +directions (height and width) but can distribute its growth in the +main direction (horizontal for a row) `unevenly` among its +children. In our example case, the vertical sizer is supposed to +propagate all its height changes to only the text area, not to the +button area. This is determined by the `proportion` parameter when +adding a window (or another sizer) to a sizer. It is interpreted as a +weight factor, i.e. it can be zero, indicating that the window may not +be resized at all, or above zero. If several windows have a value +above zero, the value is interpreted relative to the sum of all weight +factors of the sizer, so when adding two windows with a value of 1, +they will both get resized equally much and each half as much as the +sizer owning them. Then what do we do when a column sizer changes its +width? This behaviour is controlled by `flags` (the second parameter +of the `Add()` function): Zero or no flag indicates that the window +will preserve it is original size, ``wx.GROW`` flag (same as ``wx.EXPAND``) +forces the window to grow with the sizer, and ``wx.SHAPED`` flag tells +the window to change it is size proportionally, preserving original +aspect ratio. When ``wx.GROW`` flag is not used, the item can be aligned +within available space. ``wx.ALIGN_LEFT``, ``wx.ALIGN_TOP``, +``wx.ALIGN_RIGHT``, ``wx.ALIGN_BOTTOM``, ``wx.ALIGN_CENTER_HORIZONTAL`` and +``wx.ALIGN_CENTER_VERTICAL`` do what they say. ``wx.ALIGN_CENTRE`` (same as +``wx.ALIGN_CENTER``) is defined as (``wx.ALIGN_CENTER_HORIZONTAL`` | +``wx.ALIGN_CENTER_VERTICAL``). Default alignment is ``wx.ALIGN_LEFT`` | +``wx.ALIGN_TOP``. -As mentioned above, any window belonging to a sizer may have a border, and it can be specified which of the four sides may have this border, -using the ``TOP``, ``LEFT``, ``RIGHT`` and ``BOTTOM`` constants or ``ALL`` for all directions (and you may also use ``NORTH``, ``WEST`` etc instead). -These flags can be used in combination with the alignment flags above as the second parameter of the `Add()` method using the binary or operator ``|``. -The sizer of the border also must be made known, and it is the third parameter in the `Add()` method. This means, that the entire behaviour of a -sizer and its children can be controlled by the three parameters of the `Add()` method. +As mentioned above, any window belonging to a sizer may have a border, +and it can be specified which of the four sides may have this border, +using the ``wx.TOP``, ``wx.LEFT``, ``wx.RIGHT`` and ``wx.BOTTOM`` +constants or ``wx.ALL`` for all directions (and you may also use +``wx.NORTH``, ``wx.WEST`` etc. instead). These flags can be used in +combination with the alignment flags above as the second parameter of +the `Add()` method using the binary or operator ``|``. The sizer of +the border also must be made known, and it is the third parameter in +the `Add()` method. This means, that the entire behaviour of a sizer +and its children can be controlled by the three parameters of the +`Add()` method. Example:: - # We want to get a dialog that is stretchable because it - # has a text ctrl at the top and two buttons at the bottom. + # We want to get a dialog that is stretchable because it + # has a text ctrl at the top and two buttons at the bottom. - class MyDialog(wx.Dialog): - - def __init__(self, parent, id, title): - - wx.Dialog(parent, id, title, wx.DefaultPosition, wx.DefaultSize, - wx.DEFAULT_DIALOG_STYLE | wx.RESIZE_BORDER) + class MyDialog(wx.Dialog): + + def __init__(self, parent, id, title): + + wx.Dialog(parent, id, title, wx.DefaultPosition, wx.DefaultSize, + wx.DEFAULT_DIALOG_STYLE | wx.RESIZE_BORDER) - topsizer = wx.BoxSizer(wx.VERTICAL) + topsizer = wx.BoxSizer(wx.VERTICAL) - # create text ctrl with minimal size 100x60 - topsizer.Add( - wx.TextCtrl(self, -1, "My text.", wx.DefaultPosition, wx.Size(100,60), wx.TE_MULTILINE), - 1, # make vertically stretchable - wx.EXPAND | # make horizontally stretchable - wx.ALL, # and make border all around - 10) # set border width to 10 + # create text ctrl with minimal size 100x60 + topsizer.Add( + wx.TextCtrl(self, -1, "My text.", wx.DefaultPosition, wx.Size(100,60), wx.TE_MULTILINE), + 1, # make vertically stretchable + wx.EXPAND | # make horizontally stretchable + wx.ALL, # and make border all around + 10) # set border width to 10 - button_sizer = wx.BoxSizer(wx.HORIZONTAL) - button_sizer.Add( - wx.Button(self, wx.ID_OK, "OK"), - 0, # make horizontally unstretchable - wx.ALL, # make border all around (implicit top alignment) - 10) # set border width to 10 - button_sizer.Add( - wx.Button(self, wx.ID_CANCEL, "Cancel"), - 0, # make horizontally unstretchable - wx.ALL, # make border all around (implicit top alignment) - 10) # set border width to 10 + button_sizer = wx.BoxSizer(wx.HORIZONTAL) + button_sizer.Add( + wx.Button(self, wx.ID_OK, "OK"), + 0, # make horizontally unstretchable + wx.ALL, # make border all around (implicit top alignment) + 10) # set border width to 10 + button_sizer.Add( + wx.Button(self, wx.ID_CANCEL, "Cancel"), + 0, # make horizontally unstretchable + wx.ALL, # make border all around (implicit top alignment) + 10) # set border width to 10 - topsizer.Add( - button_sizer, - 0, # make vertically unstretchable - wx.ALIGN_CENTER) # no border and centre horizontally + topsizer.Add( + button_sizer, + 0, # make vertically unstretchable + wx.ALIGN_CENTER) # no border and centre horizontally - self.SetSizerAndFit(topsizer) # use the sizer for layout and size window - # accordingly and prevent it from being resized - # to smaller size - + self.SetSizerAndFit(topsizer) # use the sizer for layout and size window + # accordingly and prevent it from being resized + # to smaller size + -Note that the new way of specifying flags to :ref:`Sizer` is via :ref:`SizerFlags`. This class greatly eases the burden of passing flags to a :ref:`Sizer`. +Note that the new way of specifying flags to :ref:`wx.Sizer` is via +:ref:`wx.SizerFlags`. This class greatly eases the burden of passing +flags to a :ref:`wx.Sizer`. -Here's how you'd do the previous example with :ref:`SizerFlags`:: +Here's how you'd do the previous example with :ref:`wx.SizerFlags`:: - # We want to get a dialog that is stretchable because it - # has a text ctrl at the top and two buttons at the bottom. + # We want to get a dialog that is stretchable because it + # has a text ctrl at the top and two buttons at the bottom. - class MyDialog(wx.Dialog): - - def __init__(self, parent, id, title): - - wx.Dialog(parent, id, title, wx.DefaultPosition, wx.DefaultSize, - wx.DEFAULT_DIALOG_STYLE | wx.RESIZE_BORDER) + class MyDialog(wx.Dialog): + + def __init__(self, parent, id, title): + + wx.Dialog(parent, id, title, wx.DefaultPosition, wx.DefaultSize, + wx.DEFAULT_DIALOG_STYLE | wx.RESIZE_BORDER) - topsizer = wx.BoxSizer(wx.VERTICAL) + topsizer = wx.BoxSizer(wx.VERTICAL) - # create text ctrl with minimal size 100x60 - topsizer.Add( - wx.TextCtrl(self, -1, "My text.", wx.DefaultPosition, wx.Size(100,60), wx.TE_MULTILINE), - wx.SizerFlags(1).Align().Expand().Border(wx.ALL, 10)) + # create text ctrl with minimal size 100x60 + topsizer.Add( + wx.TextCtrl(self, -1, "My text.", wx.DefaultPosition, wx.Size(100,60), wx.TE_MULTILINE), + wx.SizerFlags(1).Align().Expand().Border(wx.ALL, 10)) - button_sizer = wx.BoxSizer(wx.HORIZONTAL) - button_sizer.Add( - wx.Button(self, wx.ID_OK, "OK"), - wx.SizerFlags(0).Align().Border(wx.ALL, 10)) - - button_sizer.Add( - wx.Button(self, wx.ID_CANCEL, "Cancel"), - wx.SizerFlags(0).Align().Border(wx.ALL, 10)) + button_sizer = wx.BoxSizer(wx.HORIZONTAL) + button_sizer.Add( + wx.Button(self, wx.ID_OK, "OK"), + wx.SizerFlags(0).Align().Border(wx.ALL, 10)) + + button_sizer.Add( + wx.Button(self, wx.ID_CANCEL, "Cancel"), + wx.SizerFlags(0).Align().Border(wx.ALL, 10)) - topsizer.Add( - button_sizer, - wx.SizerFlags(0).Center()) + topsizer.Add( + button_sizer, + wx.SizerFlags(0).Center()) - self.SetSizerAndFit(topsizer) # use the sizer for layout and set size and hints + self.SetSizerAndFit(topsizer) # use the sizer for layout and set size and hints Other Types of Sizers --------------------- -:ref:`GridSizer` is a sizer which lays out its children in a two-dimensional table with all table fields having the same size, i.e. -the width of each field is the width of the widest child, the height of each field is the height of the tallest child. +:ref:`wx.GridSizer` is a sizer which lays out its children in a +two-dimensional table with all table fields having the same size, i.e. +the width of each field is the width of the widest child, the height +of each field is the height of the tallest child. -:ref:`FlexGridSizer` is a sizer which lays out its children in a two-dimensional table with all table fields in one row having the -same height and all fields in one column having the same width, but all rows or all columns are not necessarily the same height or -width as in the :ref:`GridSizer`. +:ref:`wx.FlexGridSizer` is a sizer which lays out its children in a +two-dimensional table with all table fields in one row having the same +height and all fields in one column having the same width, but all +rows or all columns are not necessarily the same height or width as in +the :ref:`wx.GridSizer`. -:class:`StaticBoxSizer` is a sizer derived from :ref:`BoxSizer` but adds a static box around the sizer. Note that this static box -has to be created separately. +:class:`wx.StaticBoxSizer` is a sizer derived from :ref:`wx.BoxSizer` +but adds a static box around the sizer. Note that this static box has +to be created separately. -:ref:`GridBagSizer` is a rather special kind of sizer which, unlike the other classes, allows to directly put the elements at the -given position in the sizer. Please see its documentation for more details. +:ref:`wx.GridBagSizer` is a rather special kind of sizer which, unlike +the other classes, allows to directly put the elements at the given +position in the sizer. Please see its documentation for more details. CreateButtonSizer ----------------- -As a convenience, :meth:`Dialog.CreateButtonSizer` (flags) can be used to create a standard button sizer in which standard buttons -are displayed. The following flags can be passed to this method:: +As a convenience, :meth:`wx.Dialog.CreateButtonSizer`\ (flags) can be +used to create a standard button sizer in which standard buttons are +displayed. The following flags can be passed to this method:: - wx.YES_NO # Add Yes/No subpanel - wx.YES # return wx.ID_YES - wx.NO # return wx.ID_NO - wx.NO_DEFAULT # make the wx.NO button the default, - # otherwise wx.YES or wx.OK button will be default + wx.YES_NO # Add Yes/No subpanel + wx.YES # return wx.ID_YES + wx.NO # return wx.ID_NO + wx.NO_DEFAULT # make the wx.NO button the default, + # otherwise wx.YES or wx.OK button will be default - wx.OK # return wx.ID_OK - wx.CANCEL # return wx.ID_CANCEL - wx.HELP # return wx.ID_HELP + wx.OK # return wx.ID_OK + wx.CANCEL # return wx.ID_CANCEL + wx.HELP # return wx.ID_HELP - wx.FORWARD # return wx.ID_FORWARD - wx.BACKWARD # return wx.ID_BACKWARD - wx.SETUP # return wx.ID_SETUP - wx.MORE # return wx.ID_MORE + wx.FORWARD # return wx.ID_FORWARD + wx.BACKWARD # return wx.ID_BACKWARD + wx.SETUP # return wx.ID_SETUP + wx.MORE # return wx.ID_MORE