andlabs-ui/redo/sizing_unix.go

// +build !windows,!darwin

// 23 february 2014

package ui

// #include "gtk_unix.h"
import "C"

type sizing struct {
	sizingbase

	// for size calculations
	// gtk+ needs nothing

	// for the actual resizing
	shouldVAlignTop	bool
}

const (
	gtkXMargin = 12
	gtkYMargin = 12
	gtkXPadding = 12
	gtkYPadding = 6
)

func (c *container) beginResize() (d *sizing) {
	d = new(sizing)
	if spaced {
		d.xmargin = gtkXMargin
		d.ymargin = gtkYMargin
		d.xpadding = gtkXPadding
		d.ypadding = gtkYPadding
	}
	return d
}

func (c *container) translateAllocationCoords(allocations []*allocation, winwidth, winheight int) {
	// no need for coordinate conversion with gtk+
}

func (w *widgetbase) allocate(x int, y int, width int, height int, d *sizing) []*allocation {
        return []*allocation{&allocation{
                x:      x,
                y:      y,
                width:  width,
                height: height,
                this:   w,
        }}
}

func (w *widgetbase) commitResize(c *allocation, d *sizing) {
	// as we resize on size-allocate, we have to also use size-allocate on our children
	// this is fine anyway; in fact, this allows us to move without knowing what the container is!
	// this is what GtkBox does anyway
	// thanks to tristan in irc.gimp.net/#gtk+

	var r C.GtkAllocation

	r.x = C.int(c.x)
	r.y = C.int(c.y)
	r.width = C.int(c.width)
	r.height = C.int(c.height)
	C.gtk_widget_size_allocate(w.widget, &r)
}

func (w *widgetbase) getAuxResizeInfo(d *sizing) {
//TODO
//	d.shouldVAlignTop = (s.ctype == c_listbox) || (s.ctype == c_area)
	d.shouldVAlignTop = false
}

// GTK+ 3 makes this easy: controls can tell us what their preferred size is!
// ...actually, it tells us two things: the "minimum size" and the "natural size".
// The "minimum size" is the smallest size we /can/ display /anything/. The "natural size" is the smallest size we would /prefer/ to display.
// The difference? Minimum size takes into account things like truncation with ellipses: the minimum size of a label can allot just the ellipses!
// So we use the natural size instead.
// There is a warning about height-for-width controls, but in my tests this isn't an issue.
// For Areas, we manually save the Area size and use that, just to be safe.

// We don't need to worry about y-offset because label alignment is "vertically center", which GtkLabel does for us.

func (w *widgetbase) preferredSize(d *sizing) (width int, height int) {
//TODO
/*
	if s.ctype == c_area {
		return s.areawidth, s.areaheight
	}
*/

	var r C.GtkRequisition

	C.gtk_widget_get_preferred_size(w.widget, nil, &r)
	return int(r.width), int(r.height)
}