andlabs-ui/container.go

// 25 june 2014

package ui

type allocation struct {
	x        int
	y        int
	width    int
	height   int
	this     Control
	neighbor Control
}

type sizingbase struct {
	xmargin       int
	ymargintop    int
	ymarginbottom int
	xpadding      int
	ypadding      int
}

type controlSizing interface {
	allocate(x int, y int, width int, height int, d *sizing) []*allocation
	preferredSize(*sizing) (int, int)
	commitResize(*allocation, *sizing)
	getAuxResizeInfo(*sizing)
}

// A container hosts a Control and resizes that Control based on changes in size to the parent Window.
// container is used by Window, Tab, and Group to contain and control their respective Controls.
// Tab and Group use containers for their content; as such, their commitResize() functions should only change the size of the Tab and Group themselves, and have their containers do the real work.
// All containers must embed containerbase.
type containerbase struct {
	child Control
}

// set to true to apply spacing to all windows
var spaced bool = false

func (c *container) resize(x, y, width, height int) {
	if c.child == nil { // no children; nothing to do
		return
	}
	d := c.beginResize()
	allocations := c.child.allocate(x+d.xmargin, y+d.ymargintop,
		width-(2*d.xmargin), height-d.ymargintop-d.ymarginbottom, d)
	c.translateAllocationCoords(allocations, width, height)
	// move in reverse so as to approximate right->left order so neighbors make sense
	for i := len(allocations) - 1; i >= 0; i-- {
		allocations[i].this.commitResize(allocations[i], d)
	}
}