CELL

Base element for layout design. It provides complex layout capabilities with embedded rows and columns, and relative pixel-positioning. 

CELL is an invisible element, which is used for the calculation of the position of other elements inside it (other CELLs or widgets). CELL can have one of three layout_types that defines how inner elements are placed: in a row, column, or layer_stack (one over another).

You can write <CELL layout_type="row"> or <ROW>. So, there are three shortcut elements for CELL named ROW, COLUMN, and LAYER_STACK. By the way, default CELL's layout_type is "column", so COLUMN or CELL are usually the same. The only difference is that you can't change layout_type for COLUMN, as it is fixed.

Many of KUIML elements inherit CELL properties, so you can use them inside WIDGETs or SKIN (which is a root CELL and can also have layout_type, font_face, etc).

See some examples below, they show most of the KUIML layout possibilities.

Attributes brief detailed show all inherited

	Name	Description	Default
Properties Relative to Parent Cell
	v_align	Vertical alignment of the cell in its parent cell	center
	h_align	Horizontal alignment of the cell in its parent cell	center
	h_position	Horizontal position of the cell in its parent cellIf defined, it deactivates the h_align property. Use this attribute for horizontal pixel-positioning. The position is relative to the parent cell
	v_position	Vertical position of the cell in its parent cellIf defined, it deactivates the v_align property. Use this attribute for vertical pixel-positioning. The position is relative to the parent cell
	h_offset	horizontal offset of the cell from the position computed by the layout engineUsing this property lets you move a cell without changing the layout around it. The position is relative to the parent cell	0
	v_offset	vertical offset of the cell from the position computed by the layout engineUsing this property lets you move a cell without changing the layout around it. The position is relative to the parent cell	0
	flex	flexibility of the cellThis attribute is used when the parent cell is a row or a column and has free space to distribute to children cells (for example for a fixed size parent cell that is larger than the sum of its children cell sizes). The remaining space will be distributed among children cells according to the flex attribute value	0
	display	include/exclude the cell from the layoutWhen set to false, the content of the cell is not displayed (not visible) AND is not taken into account to compute the layout (the cell is ignored)	true
Cell Properties
	layout_type	Selects a layout type: row, column or layer_stackDetermines how the children cells will be disposed inside the cell: as a row, a column or a stack of layers (each cell on top of each other, the first cell in the background, and the last one on the foreground)	column
	width	Forced width of the cellIf not present, the width will be automatically computed from the children cells widths and layout rules
	min_width	minimum width allowed for the cellWhen set, the layout engine will ensure that the width of the cell is not smaller than min_width pixels
	max_width	maximum width allowed for the cellWhen set, the layout engine will ensure that the width of the cell is not larger than max_width pixels
	height	Forced height of the cellIf not present, the height will be automatically computed from the children cells heights and layout rules
	min_height	minimum height allowed for the cellWhen set, the layout engine will ensure that the width of the cell is not smaller than min_height pixels
	max_height	maximum height allowed for the cellWhen set, the layout engine will ensure that the width of the cell is not larger than max_height pixels
	margin	margin of the cellMay be overridden by the h_margin or v_margin attributes	0
	h_margin	Horizontal margin of the cell	0
	v_margin	Vertical margin of the cell	0
	spacing	Space between children cells	0
	spacing_flex	Flex value to allocate extra space between children cellsSee the flex attribute for more details	0
	internal_v_align	Vertical alignment of children cells group inside the cellThis attribute is useful only if the cell has a fixed size, and the sum of the sizes of the layouted children cells is different from the cell size. In this case you may want to choose how you align the children cells group inside the parent cell. Used only for 'column' type cell, the horizontal alignment being set individually for each child cell	center
	internal_h_align	Horizontal alignment of children cells group inside the cellThis attribute is useful only if the cell has a fixed size, and the sum of the sizes of the layouted children cells is different from the cell size. In this case you may want to choose how you align the children cells group inside the parent cell. Used only for 'row' type cell, the vertical alignment being set individually for each child cell	center
	reflow	when set to true, the layout engine will treat chidren cell as reflowable elements. For a fixed height column, the width is computed accordingly, and for a fixed width row, the height is computed accordinglyvalid only for columns with fixed height or rows with fixed width	false
	flip	display children cells in reverse order (right to left or bottom to top)currently valid only for COLUMN and ROW elements	false
Inheritable properties: these text properties are inherited by children cells (and can be overridden)
	font_face	Name of the font for text contained in the cell and sub cellsFonts are not the same on all systems, so you should carefuly select the fonts or ensure that users have specific fonts installed	empty
	font_size	Size of the font for any text contained in the cellIf the value starts with + or -, the resulting font size is incremented by this value from the current font size. If the value ends with a %, the resulting font size is the corresponding proportion of the current font size. This value is inherited by children cells but can be overridden	System...
	font_size_mode	Defines how font size is computed to select the right font.Default value is cell mode for backward compatibility reasons but it has been deprecated. It is however recommended to use "character" mode for more precise font size selection. Using the cell size to select the font is less precise and not compatible with standard font sizes expressed in character height.	cell
	font_weight	Weight of the font for any text contained in the cellThe value is inherited by children cells but can be overridden	System...
	font_style	Style of the font for any text contained in the cellThe value is inherited by children cells but can be overridden	System...
	font_quality	Quality of the fontThe value is inherited by children cells but can be overridden	System...
	font_escapement	Escapement (angle in degrees) of the fontThe value is inherited by children cells but can be overridden. If the escapement of the font is non null, the formating options of the text widgets won't apply	0
	text_decoration	Decoration of the text for any text contained in the cellThe value is inherited by children cells but can be overridden	System...
	text_color	Color of any text contained in the cellThe value is inherited by children cells but can be overridden	System...
Common attributes
	id	Identifier of the elementThe id of an element has to be globally unique. Two elements cannot have the same identifier	empty

	Name	Value type	Default	Description	Comment
Properties Relative to Parent Cell
	v_align	vertical alignment	center	Vertical alignment of the cell in its parent cell
	h_align	horizontal alignment	center	Horizontal alignment of the cell in its parent cell
	h_position	position in pixels		Horizontal position of the cell in its parent cell	If defined, it deactivates the h_align property. Use this attribute for horizontal pixel-positioning. The position is relative to the parent cell
	v_position	position in pixels		Vertical position of the cell in its parent cell	If defined, it deactivates the v_align property. Use this attribute for vertical pixel-positioning. The position is relative to the parent cell
	h_offset	position in pixels	0	horizontal offset of the cell from the position computed by the layout engine	Using this property lets you move a cell without changing the layout around it. The position is relative to the parent cell
	v_offset	position in pixels	0	vertical offset of the cell from the position computed by the layout engine	Using this property lets you move a cell without changing the layout around it. The position is relative to the parent cell
	flex	real number	0	flexibility of the cell	This attribute is used when the parent cell is a row or a column and has free space to distribute to children cells (for example for a fixed size parent cell that is larger than the sum of its children cell sizes). The remaining space will be distributed among children cells according to the flex attribute value
	display	boolean	true	include/exclude the cell from the layout	When set to false, the content of the cell is not displayed (not visible) AND is not taken into account to compute the layout (the cell is ignored)
Cell Properties
	layout_type	'row' or 'column' or 'layer_stack'	column	Selects a layout type: row, column or layer_stack	Determines how the children cells will be disposed inside the cell: as a row, a column or a stack of layers (each cell on top of each other, the first cell in the background, and the last one on the foreground)
	width	number of pixels or percentage (1.1)		Forced width of the cell	If not present, the width will be automatically computed from the children cells widths and layout rules
	min_width	number of pixels		minimum width allowed for the cell	When set, the layout engine will ensure that the width of the cell is not smaller than min_width pixels
	max_width	number of pixels		maximum width allowed for the cell	When set, the layout engine will ensure that the width of the cell is not larger than max_width pixels
	height	number of pixels or percentage (1.1)		Forced height of the cell	If not present, the height will be automatically computed from the children cells heights and layout rules
	min_height	number of pixels		minimum height allowed for the cell	When set, the layout engine will ensure that the width of the cell is not smaller than min_height pixels
	max_height	number of pixels		maximum height allowed for the cell	When set, the layout engine will ensure that the width of the cell is not larger than max_height pixels
	margin	number of pixels	0	margin of the cell	May be overridden by the h_margin or v_margin attributes
	h_margin	number of pixels	0	Horizontal margin of the cell
	v_margin	number of pixels	0	Vertical margin of the cell
	spacing	number of pixels	0	Space between children cells
	spacing_flex	real number	0	Flex value to allocate extra space between children cells	See the flex attribute for more details
	internal_v_align	vertical alignment	center	Vertical alignment of children cells group inside the cell	This attribute is useful only if the cell has a fixed size, and the sum of the sizes of the layouted children cells is different from the cell size. In this case you may want to choose how you align the children cells group inside the parent cell. Used only for 'column' type cell, the horizontal alignment being set individually for each child cell
	internal_h_align	horizontal alignment	center	Horizontal alignment of children cells group inside the cell	This attribute is useful only if the cell has a fixed size, and the sum of the sizes of the layouted children cells is different from the cell size. In this case you may want to choose how you align the children cells group inside the parent cell. Used only for 'row' type cell, the vertical alignment being set individually for each child cell
	reflow	boolean	false	when set to true, the layout engine will treat chidren cell as reflowable elements. For a fixed height column, the width is computed accordingly, and for a fixed width row, the height is computed accordingly	valid only for columns with fixed height or rows with fixed width
	flip	boolean	false	display children cells in reverse order (right to left or bottom to top)	currently valid only for COLUMN and ROW elements
Inheritable properties: these text properties are inherited by children cells (and can be overridden)
	font_face	string	empty	Name of the font for text contained in the cell and sub cells	Fonts are not the same on all systems, so you should carefuly select the fonts or ensure that users have specific fonts installed
	font_size	number of pixels or percentage (1.2.2), with or without +/- sign (1.2.2)	System default value	Size of the font for any text contained in the cell	If the value starts with + or -, the resulting font size is incremented by this value from the current font size. If the value ends with a %, the resulting font size is the corresponding proportion of the current font size. This value is inherited by children cells but can be overridden
	font_size_mode	"cell" or "character"	cell	Defines how font size is computed to select the right font.	Default value is cell mode for backward compatibility reasons but it has been deprecated. It is however recommended to use "character" mode for more precise font size selection. Using the cell size to select the font is less precise and not compatible with standard font sizes expressed in character height.
	font_weight	'bold' or 'normal'	System default value	Weight of the font for any text contained in the cell	The value is inherited by children cells but can be overridden
	font_style	'italic' or 'normal'	System default value	Style of the font for any text contained in the cell	The value is inherited by children cells but can be overridden
	font_quality	'default' or 'no_anti_alias' or 'anti_alias' or 'cleartype'	System default value	Quality of the font	The value is inherited by children cells but can be overridden
	font_escapement	real number	0	Escapement (angle in degrees) of the font	The value is inherited by children cells but can be overridden. If the escapement of the font is non null, the formating options of the text widgets won't apply
	text_decoration	'underline' or 'none'	System default value	Decoration of the text for any text contained in the cell	The value is inherited by children cells but can be overridden
	text_color	color	System default value	Color of any text contained in the cell	The value is inherited by children cells but can be overridden
Common attributes
	id	identifier	empty	Identifier of the element	The id of an element has to be globally unique. Two elements cannot have the same identifier

Examples

As CELLs are invisible, let's use a few WIDGET elements with background_color attribute for the following examples. Instead of these colored squares you can use knobs, text and other elements of your layout.

The SKIN is the root cell and its layout_type is "column" by default.

In a row

If we want to place them horizontally we can either set SKIN layout_type="row", or add another ROW element (or any CELL-ish element with layout_type="row").

Just for fun let's reverse them using <ROW flip="true"> (or flip="1").

Let's make two rows and add some spacing between elements. 

As a stack

Let's put elements one over another.

As you see they are perfectly centered. We may align them inside the parent cell using h/v_align. Also we can change their position using h/v_offset (relative to calculated position) or h/v_position (relative to parent element).

The cool thing about h/v_offset is that you can change that dynamically, and thus move/animate an object.

Exploring flex and display

If we set a parent element to a width (or height) greater than sum of its childrens, we can use the flex attribute to distribute that extra space between children (so that they stretch to take that space). We can also use display attribute to dynamically change the layout.

Note that WIDGET-type elements also have "visible" attribute, which can show or hide the element without changing the layout.

To illustrate spacing_flex attribute we also need a parent with a size greater than sum of its children.

Here we used a margin to create a blue "border" (we just added more space around the the top blue WIDGET to make it bigger than inner white WIDGET, and so the blue is partly visible). There are h_margin and v_margin attributes if you want to set them separately.

Size of the element

We can set the width or the height of the element in pixels or percents (relative to parent). If we omit width or height attributes, they will be calculated using the size of the inner contents.

We can also use min_width, max_width and min_height, max_height attributes designing the layout. They can be set in pixels only.

Content alignment

Instead of using h_align and v_align on each element individually, you can set the alignment in the parent cell, usign internal_h_align (works for rows only) and internal_v_align (for columns only).

Note that the TEXT element inherits CELL attributes, so you can set fixed width or height for the TEXT and use its text_h_align or text_v_align (common for all text widgets) attrubutes for further text alignment.

Magical reflow

This is a trick that can be used for fixed width rows or fixed height columns: if the content doesn't fit, it goes to the "next line" using reflow.

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