70 lines
2.3 KiB
Go
70 lines
2.3 KiB
Go
|
// 4 august 2014
|
||
|
|
|
||
|
|
package ui
|
||
|
|
|
||
|
|
// #include "winapi_windows.h"
|
||
|
|
import "C"
|
||
|
|
|
||
|
|
type sizing struct {
|
||
|
|
sizingbase
|
||
|
|
|
||
|
|
// for size calculations
|
||
|
|
baseX C.int
|
||
|
|
baseY C.int
|
||
|
|
internalLeading C.LONG // for Label; see Label.commitResize() for details
|
||
|
|
|
||
|
|
// for the actual resizing
|
||
|
|
// possibly the HDWP
|
||
|
|
}
|
||
|
|
|
||
|
|
// For Windows, Microsoft just hands you a list of preferred control sizes as part of the MSDN documentation and tells you to roll with it.
|
||
|
|
// These sizes are given in "dialog units", which are independent of the font in use.
|
||
|
|
// We need to convert these into standard pixels, which requires we get the device context of the OS window.
|
||
|
|
// References:
|
||
|
|
// - http://msdn.microsoft.com/en-us/library/ms645502%28VS.85%29.aspx - the calculation needed
|
||
|
|
// - http://support.microsoft.com/kb/125681 - to get the base X and Y
|
||
|
|
// (thanks to http://stackoverflow.com/questions/58620/default-button-size)
|
||
|
|
// In my tests (see https://github.com/andlabs/windlgunits), the GetTextExtentPoint32() option for getting the base X produces much more accurate results than the tmAveCharWidth option when tested against the sample values given in http://msdn.microsoft.com/en-us/library/windows/desktop/dn742486.aspx#sizingandspacing, but can be off by a pixel in either direction (probably due to rounding errors).
|
||
|
|
|
||
|
|
// note on MulDiv():
|
||
|
|
// div will not be 0 in the usages below
|
||
|
|
// we also ignore overflow; that isn't likely to happen for our use case anytime soon
|
||
|
|
|
||
|
|
func fromdlgunitsX(du int, d *sizing) int {
|
||
|
|
return int(C.MulDiv(C.int(du), d.baseX, 4))
|
||
|
|
}
|
||
|
|
|
||
|
|
func fromdlgunitsY(du int, d *sizing) int {
|
||
|
|
return int(C.MulDiv(C.int(du), d.baseY, 8))
|
||
|
|
}
|
||
|
|
|
||
|
|
const (
|
||
|
|
// shared by multiple containers
|
||
|
|
marginDialogUnits = 7
|
||
|
|
paddingDialogUnits = 4
|
||
|
|
)
|
||
|
|
|
||
|
|
func beginResize(hwnd C.HWND) (d *sizing) {
|
||
|
|
var baseX, baseY C.int
|
||
|
|
var internalLeading C.LONG
|
||
|
|
|
||
|
|
d = new(sizing)
|
||
|
|
|
||
|
|
C.calculateBaseUnits(hwnd, &baseX, &baseY, &internalLeading)
|
||
|
|
d.baseX = baseX
|
||
|
|
d.baseY = baseY
|
||
|
|
d.internalLeading = internalLeading
|
||
|
|
|
||
|
|
d.xpadding = fromdlgunitsX(paddingDialogUnits, d)
|
||
|
|
d.ypadding = fromdlgunitsY(paddingDialogUnits, d)
|
||
|
|
|
||
|
|
return d
|
||
|
|
}
|
||
|
|
|
||
|
|
func marginRectDLU(r *C.RECT, top int, bottom int, left int, right int, d *sizing) {
|
||
|
|
r.left += C.LONG(fromdlgunitsX(left, d))
|
||
|
|
r.top += C.LONG(fromdlgunitsY(top, d))
|
||
|
|
r.right -= C.LONG(fromdlgunitsX(right, d))
|
||
|
|
r.bottom -= C.LONG(fromdlgunitsY(bottom, d))
|
||
|
|
}
|