andlabs-ui/redo/label_darwin.go

// 16 july 2014

package ui

import (
	"unsafe"
)

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

type label struct {
	_id			C.id
	standalone	bool
}

func finishNewLabel(text string, standalone bool) *label {
	l := &label{
		_id:			C.newLabel(),
		standalone:	standalone,
	}
	l.SetText(text)
	return l
}

func newLabel(text string) Label {
	return finishNewLabel(text, false)
}

func newStandaloneLabel(text string) Label {
	return finishNewLabel(text, true)
}

func (l *label) Text() string {
	return C.GoString(C.textFieldText(l._id))
}

func (l *label) SetText(text string) {
	ctext := C.CString(text)
	defer C.free(unsafe.Pointer(ctext))
	C.textFieldSetText(l._id, ctext)
}

func (l *label) id() C.id {
	return l._id
}

func (l *label) setParent(p *controlParent) {
	basesetParent(l, p)
}

func (l *label) allocate(x int, y int, width int, height int, d *sizing) []*allocation {
	return baseallocate(l, x, y, width, height, d)
}

func (l *label) preferredSize(d *sizing) (width, height int) {
	return basepreferredSize(l, d)
}

func (l *label) commitResize(c *allocation, d *sizing) {
	if !l.standalone && c.neighbor != nil {
		c.neighbor.getAuxResizeInfo(d)
		if d.neighborAlign.baseline != 0 {		// no adjustment needed if the given control has no baseline
			// in order for the baseline value to be correct, the label MUST BE AT THE HEIGHT THAT OS X WANTS IT TO BE!
			// otherwise, the baseline calculation will be relative to the bottom of the control, and everything will be wrong
			origsize := C.controlPreferredSize(l._id)
			c.height = int(origsize.height)
			newrect := C.struct_xrect{
				x:		C.intptr_t(c.x),
				y:		C.intptr_t(c.y),
				width:	C.intptr_t(c.width),
				height:	C.intptr_t(c.height),
			}
			ourAlign := C.alignmentInfo(l._id, newrect)
			// we need to find the exact Y positions of the baselines
			// fortunately, this is easy now that (x,y) is the bottom-left corner
			thisbasey := ourAlign.rect.y + ourAlign.baseline
			neighborbasey := d.neighborAlign.rect.y + d.neighborAlign.baseline
			// now the amount we have to move the label down by is easy to find
			yoff := neighborbasey - thisbasey
			// and we just add that
			c.y += int(yoff)
		}
		// in the other case, the most correct thing would be for Label to be aligned to the alignment rect, but I can't get this working, and it looks fine as it is anyway
	}
	basecommitResize(l, c, d)
}

func (l *label) getAuxResizeInfo(d *sizing) {
	basegetAuxResizeInfo(l, d)
}