Sprite:setLayoutConstraints

Available since: Gideros 2018.9

Class: Sprite

Description

This function specify the child placement rules within the grid defined on its parent by Sprite:setLayoutParameters.

Gideros layout system is heavily based on Java GridBagLayout principle. See here for more explanation: https://www.math.uni-hamburg.de/doc/java/tutorial/uiswing/layout/gridbag.html

The constraint table can contain the following fields:

• gridx: The 0-based index of the column the child must be placed into
• gridy: The 0-based index of the row the child must be placed into
• gridwidth: The number of column this child will take
• gridheight: The number of row this child will take
• weightx: The horizontal weight of the child. Used to distribute extra space among children
• weighty: The vertical weight of the child. Used to distribute extra space among children
• anchor: Defines where the child should be placed inside its grid space.

Can be Sprite.LAYOUT_ANCHOR_NORTHWEST, Sprite.LAYOUT_ANCHOR_NORTH, Sprite.LAYOUT_ANCHOR_NORTHEAST, Sprite.LAYOUT_ANCHOR_WEST, Sprite.LAYOUT_ANCHOR_CENTER, Sprite.LAYOUT_ANCHOR_EAST, Sprite.LAYOUT_ANCHOR_SOUTHWEST, Sprite.LAYOUT_ANCHOR_SOUTH or Sprite.LAYOUT_ANCHOR_SOUTHEAST

• fill: In which directions the child should be expanded to fit the grid space.

Can be Sprite.LAYOUT_FILL_NONE, Sprite.LAYOUT_FILL_HORIZONTAL, Sprite.LAYOUT_FILL_VERTICAL or Sprite.LAYOUT_FILL_BOTH

• ipadx: Internal horizontal padding
• ipady: Internal vertical padding
• minWidth: Minimum width
• minHeight: Minimum height
• prefWidth: Preferred width
• prefHeight: Preferred height
• insetTop: the top margin
• insetLeft: the left margin
• insetBottom: the bottom margin
• insetRight: the right margin

Specifying a nil table will clear layout constraints.
When a Sprite is resized by the layout system, an Event.LAYOUT_RESIZED is triggered.

Sprite:setLayoutConstraints(constraints)

Parameters

constraints: (table) Table of layout constraints.

Examples

Example: pixels

• 

-- LAYOUT CONSTRAINTS @Nanocore
-- BUTTONS HOLDER
local myholder = Pixel.new(0x0, 0.5, 256, 256)
myholder:setPosition(8, 8)
myholder:setLayoutParameters({
	columnWeights = {1, 1, 1}, -- 3 columns
	rowWeights = {1, 1, 1, 1}, -- 4 rows
	columnWidths = {32, 32, 32}, -- min columns width
	rowHeights = {32, 32, 32, 32}, -- min rows width
})

-- BUTTONS
local mybtn1 = Pixel.new(0xff0000, 1, 32, 32)
mybtn1:setLayoutConstraints({
	gridx = 0,
	gridy = 0,
	gridwidth = 2,
	gridheight = 2,
	anchor = Sprite.LAYOUT_ANCHOR_NORTHWEST,
	fill = Sprite.LAYOUT_FILL_BOTH,
})
myholder:addChild(mybtn1)

local mybtn2 = Pixel.new(0x00ff00, 1, 32, 32)
mybtn2:setLayoutConstraints({
	gridx = 1,
	gridy = 2,
	gridwidth = 1,
	anchor = Sprite.LAYOUT_ANCHOR_NORTHWEST,
	fill = Sprite.LAYOUT_FILL_VERTICAL,
})
myholder:addChild(mybtn2)

local mybtn3 = Pixel.new(0x0000ff, 1, 32, 32)
mybtn3:setLayoutConstraints({
	gridx = 2,
	gridy = 3,
	gridwidth = 1,
	anchor = Sprite.LAYOUT_ANCHOR_NORTHWEST,
	fill = Sprite.LAYOUT_FILL_BOTH,
})
myholder:addChild(mybtn3)

-- ADD TO STAGE
stage:addChild(myholder)