andlabs-ui/button_windows.go

100 lines
2.1 KiB
Go

// 15 july 2014
package ui
import (
"unsafe"
)
// #include "winapi_windows.h"
import "C"
type button struct {
_hwnd C.HWND
_textlen C.LONG
clicked *event
}
var buttonclass = toUTF16("BUTTON")
func newButton(text string) *button {
hwnd := C.newControl(buttonclass,
C.BS_PUSHBUTTON | C.WS_TABSTOP,
0)
b := &button{
_hwnd: hwnd,
clicked: newEvent(),
}
b.SetText(text)
C.controlSetControlFont(b._hwnd)
C.setButtonSubclass(b._hwnd, unsafe.Pointer(b))
return b
}
func (b *button) OnClicked(e func()) {
b.clicked.set(e)
}
func (b *button) Text() string {
return baseText(b)
}
func (b *button) SetText(text string) {
baseSetText(b, text)
}
//export buttonClicked
func buttonClicked(data unsafe.Pointer) {
b := (*button)(data)
b.clicked.fire()
}
func (b *button) hwnd() C.HWND {
return b._hwnd
}
func (b *button) textlen() C.LONG {
return b._textlen
}
func (b *button) settextlen(len C.LONG) {
b._textlen = len
}
func (b *button) setParent(p *controlParent) {
basesetParent(b, p)
}
func (b *button) allocate(x int, y int, width int, height int, d *sizing) []*allocation {
return baseallocate(b, x, y, width, height, d)
}
const (
// from http://msdn.microsoft.com/en-us/library/windows/desktop/dn742486.aspx#sizingandspacing
buttonHeight = 14
)
func (b *button) preferredSize(d *sizing) (width, height int) {
// comctl32.dll version 6 thankfully provides a method to grab this...
var size C.SIZE
size.cx = 0 // explicitly ask for ideal size
size.cy = 0
if C.SendMessageW(b._hwnd, C.BCM_GETIDEALSIZE, 0, C.LPARAM(uintptr(unsafe.Pointer(&size)))) != C.FALSE {
return int(size.cx), int(size.cy)
}
// that failed, fall back
println("message failed; falling back")
// don't worry about the error return from GetSystemMetrics(); there's no way to tell (explicitly documented as such)
xmargins := 2 * int(C.GetSystemMetrics(C.SM_CXEDGE))
return xmargins + int(b._textlen), fromdlgunitsY(buttonHeight, d)
}
func (b *button) commitResize(a *allocation, d *sizing) {
basecommitResize(b, a, d)
}
func (b *button) getAuxResizeInfo(d *sizing) {
basegetAuxResizeInfo(b, d)
}