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Fix icon transparency #2

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Merged
merged 1 commit into from
Oct 30, 2023
Merged

Fix icon transparency #2

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64 changes: 58 additions & 6 deletions systray_windows.go
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Original file line number Diff line number Diff line change
@@ -1,3 +1,4 @@
//go:build windows
// +build windows

package systray
Expand All @@ -22,6 +23,7 @@ var (
g32 = windows.NewLazySystemDLL("Gdi32.dll")
pCreateCompatibleBitmap = g32.NewProc("CreateCompatibleBitmap")
pCreateCompatibleDC = g32.NewProc("CreateCompatibleDC")
pCreateDIBSection = g32.NewProc("CreateDIBSection")
pDeleteDC = g32.NewProc("DeleteDC")
pSelectObject = g32.NewProc("SelectObject")

Expand Down Expand Up @@ -172,6 +174,30 @@ type point struct {
X, Y int32
}

// The BITMAPINFO structure defines the dimensions and color information for a DIB.
// https://learn.microsoft.com/en-us/windows/win32/api/wingdi/ns-wingdi-bitmapinfo
type bitmapInfo struct {
BmiHeader bitmapInfoHeader
BmiColors windows.Handle
}

// The BITMAPINFOHEADER structure contains information about the dimensions and color format of a device-independent bitmap (DIB).
// https://learn.microsoft.com/en-us/previous-versions/dd183376(v=vs.85)
// https://learn.microsoft.com/en-us/windows/win32/api/wingdi/ns-wingdi-bitmapinfoheader
type bitmapInfoHeader struct {
BiSize uint32
BiWidth int32
BiHeight int32
BiPlanes uint16
BiBitCount uint16
BiCompression uint32
BiSizeImage uint32
BiXPelsPerMeter int32
BiYPelsPerMeter int32
BiClrUsed uint32
BiClrImportant uint32
}

// Contains information about loaded resources
type winTray struct {
instance,
Expand Down Expand Up @@ -735,7 +761,7 @@ func (t *winTray) loadIconFrom(src string) (windows.Handle, error) {
return h, nil
}

func (t *winTray) iconToBitmap(hIcon windows.Handle) (windows.Handle, error) {
func iconToBitmap(hIcon windows.Handle) (windows.Handle, error) {
const SM_CXSMICON = 49
const SM_CYSMICON = 50
const DI_NORMAL = 0x3
Expand All @@ -751,10 +777,7 @@ func (t *winTray) iconToBitmap(hIcon windows.Handle) (windows.Handle, error) {
defer pDeleteDC.Call(hMemDC)
cx, _, _ := pGetSystemMetrics.Call(SM_CXSMICON)
cy, _, _ := pGetSystemMetrics.Call(SM_CYSMICON)
hMemBmp, _, err := pCreateCompatibleBitmap.Call(hDC, cx, cy)
if hMemBmp == 0 {
return 0, err
}
hMemBmp, err := create32BitHBitmap(hMemDC, int32(cx), int32(cy))
hOriginalBmp, _, _ := pSelectObject.Call(hMemDC, hMemBmp)
defer pSelectObject.Call(hMemDC, hOriginalBmp)
res, _, err := pDrawIconEx.Call(hMemDC, 0, 0, uintptr(hIcon), cx, cy, 0, uintptr(0), DI_NORMAL)
Expand All @@ -764,6 +787,35 @@ func (t *winTray) iconToBitmap(hIcon windows.Handle) (windows.Handle, error) {
return windows.Handle(hMemBmp), nil
}

// https://learn.microsoft.com/en-us/windows/win32/api/wingdi/nf-wingdi-createdibsection
func create32BitHBitmap(hDC uintptr, cx, cy int32) (uintptr, error) {
const BI_RGB uint32 = 0
const DIB_RGB_COLORS = 0
bmi := bitmapInfo{
BmiHeader: bitmapInfoHeader{
BiPlanes: 1,
BiCompression: BI_RGB,
BiWidth: cx,
BiHeight: cy,
BiBitCount: 32,
},
}
bmi.BmiHeader.BiSize = uint32(unsafe.Sizeof(bmi.BmiHeader))
var bits uintptr
hBitmap, _, err := pCreateDIBSection.Call(
hDC,
uintptr(unsafe.Pointer(&bmi)),
DIB_RGB_COLORS,
uintptr(unsafe.Pointer(&bits)),
uintptr(0),
0,
)
if hBitmap == 0 {
return 0, err
}
return hBitmap, nil
}

func registerSystray() {
if err := wt.initInstance(); err != nil {
log.Errorf("Unable to init instance: %v", err)
Expand Down Expand Up @@ -882,7 +934,7 @@ func (item *MenuItem) SetIcon(iconBytes []byte) {
return
}

h, err = wt.iconToBitmap(h)
h, err = iconToBitmap(h)
if err != nil {
log.Errorf("Unable to convert icon to bitmap: %v", err)
return
Expand Down