Added FontButton.

fontbutton.go

@@ -0,0 +1,69 @@
+// 12 december 2015
+
+package ui
+
+import (
+	"unsafe"
+)
+
+// #include <stdlib.h>
+// #include "ui.h"
+// #include "util.h"
+// extern void doFontButtonOnChanged(uiFontButton *, void *);
+// // see golang/go#19835
+// typedef void (*fontButtonCallback)(uiFontButton *, void *);
+// static inline uiFontDescriptor *pkguiNewFontDescriptor(void)
+// {
+// 	return (uiFontDescriptor *) pkguiAlloc(sizeof (uiFontDescriptor));
+// }
+// static inline void pkguiFreeFontDescriptor(uiFontDescriptor *fd)
+// {
+// 	free(fd);
+// }
+import "C"
+
+// FontButton is a Control that represents a button that the user can
+// click to select a font.
+type FontButton struct {
+	ControlBase
+	b	*C.uiFontButton
+	onChanged		func(*FontButton)
+}
+
+// NewFontButton creates a new FontButton.
+func NewFontButton() *FontButton {
+	b := new(FontButton)
+
+	b.b = C.uiNewFontButton()
+
+	C.uiFontButtonOnChanged(b.b, C.fontButtonCallback(C.doFontButtonOnChanged), nil)
+
+	b.ControlBase = NewControlBase(b, uintptr(unsafe.Pointer(b.b)))
+	return b
+}
+
+// Font returns the font currently selected in the FontButton.
+func (b *FontButton) Font() *FontDescriptor {
+	cfd := C.pkguiNewFontDescriptor()
+	defer C.pkguiFreeFontDescriptor(cfd)
+	C.uiFontButtonFont(b.b, cfd)
+	defer C.uiFreeFontButtonFont(cfd)
+	fd := &FontDescriptor{}
+	fd.fromLibui(cfd)
+	return fd
+}
+
+// OnChanged registers f to be run when the user changes the
+// currently selected font in the FontButton. Only one function can
+// be registered at a time.
+func (b *FontButton) OnChanged(f func(*FontButton)) {
+	b.onChanged = f
+}
+
+//export doFontButtonOnChanged
+func doFontButtonOnChanged(bb *C.uiFontButton, data unsafe.Pointer) {
+	b := ControlFromLibui(uintptr(unsafe.Pointer(bb))).(*FontButton)
+	if b.onChanged != nil {
+		b.onChanged(b)
+	}
+}

zz_drawtext.go

@@ -8,6 +8,8 @@ import (
 	"github.com/andlabs/ui"
 )
 
+var fontButton *ui.FontButton
+
 var attrstr *ui.AttributedString
 
 func appendWithAttributes(what string, attrs ...ui.Attribute) {
@@ -78,13 +80,7 @@ type areaHandler struct{}
 func (areaHandler) Draw(a *ui.Area, p *ui.AreaDrawParams) {
 	tl := ui.DrawNewTextLayout(&ui.DrawTextLayoutParams{
 		String:		attrstr,
-		DefaultFont:	&ui.FontDescriptor{
-			Family:	"Helvetica",
-			Size:		12,
-			Weight:	ui.TextWeightNormal,
-			Italic:	ui.TextItalicNormal,
-			Stretch:	ui.TextStretchNormal,
-		},
+		DefaultFont:	fontButton.Font(),
 		Width:		p.AreaWidth,
 		Align:		ui.DrawTextAlignLeft,
 	})
@@ -130,13 +126,17 @@ func setupUI() {
 
 	vbox := ui.NewVerticalBox()
 	vbox.SetPadded(true)
-//	hbox.Append(vbox, false)
+	hbox.Append(vbox, false)
+
+	area := ui.NewArea(areaHandler{})
+
+	fontButton = ui.NewFontButton()
+	fontButton.OnChanged(func(*ui.FontButton) {
+		area.QueueRedrawAll()
+	})
+	vbox.Append(fontButton, false)
 
 /*
-	fontButton = uiNewFontButton();
-	uiFontButtonOnChanged(fontButton, onFontChanged, NULL);
-	uiBoxAppend(vbox, uiControl(fontButton), 0);
-
 	form = uiNewForm();
 	uiFormSetPadded(form, 1);
 	// TODO on OS X if this is set to 1 then the window can't resize; does the form not have the concept of stretchy trailing space?
@@ -152,7 +152,6 @@ func setupUI() {
 	uiFormAppend(form, "Alignment", uiControl(alignment), 0);
 */
 
-	area := ui.NewArea(areaHandler{})
 	hbox.Append(area, true)
 
 	mainwin.Show()