Layouts are used to calculate and assign widget positions.
Layout class itself cannot be used directly.
You should use one of the following layout classes:
- Anchor layout:
- Box layout:
- Float layout:
- Grid layout:
- Page Layout:
- Relative layout:
- Scatter layout:
- Stack layout:
Understanding the size_hint Property in Widget¶
size_hint is a tuple of values used by
layouts to manage the sizes of their children. It indicates the size
relative to the layout’s size instead of an absolute size (in
pixels/points/cm/etc). The format is:
widget.size_hint = (width_percent, height_percent)
The percent is specified as a floating point number in the range 0-1. For example, 0.5 is 50%, 1 is 100%.
If you want a widget’s width to be half of the parent’s width and the height to be identical to the parent’s height, you would do:
widget.size_hint = (0.5, 1.0)
If you don’t want to use a size_hint for either the width or height, set the value to None. For example, to make a widget that is 250px wide and 30% of the parent’s height, do:
widget.size_hint = (None, 0.3) widget.width = 250
Kivy properties, these can also be set via
widget = Widget(size_hint=(None, 0.3), width=250)
Changed in version 1.4.1: The reposition_child internal method (made public by mistake) has been removed.
Layout interface class, used to implement every layout. See module documentation for more information.
This function is called when a layout is called by a trigger. If you are writing a new Layout subclass, don’t call this function directly but use
The function is by default called before the next frame, therefore the layout isn’t updated immediately. Anything depending on the positions of e.g. children should be scheduled for the next frame.
New in version 1.0.8.
layout_hint_with_bounds(sh_sum, available_space, min_bounded_size, sh_min_vals, sh_max_vals, hint)¶
(internal) Computes the appropriate (size) hint for all the widgets given (potential) min or max bounds on the widgets’ size. The
hintlist is updated with appropriate sizes.
It walks through the hints and for any widgets whose hint will result in violating min or max constraints, it fixes the hint. Any remaining or missing space after all the widgets are fixed get distributed to the widgets making them smaller or larger according to their size hint.
This algorithms knows nothing about the widgets other than what is passed through the input params, so it’s fairly generic for laying things out according to constraints using size hints.
- sh_sum: float
The sum of the size hints (basically
- available_space: float
The amount of pixels available for all the widgets whose size hint is not None. Cannot be zero.
- min_bounded_size: float
The minimum amount of space required according to the size_hint_min of the widgets (basically
- sh_min_vals: list or iterable
Items in the iterable are the size_hint_min for each widget. Can be None. The length should be the same as
- sh_max_vals: list or iterable
Items in the iterable are the size_hint_max for each widget. Can be None. The length should be the same as
- hint: list
A list whose size is the same as the length of
sh_min_valswhose each element is the corresponding size hint value of that element. This list is updated in place with correct size hints that ensure the constraints are not violated.
hintis updated in place.