erm/vendor/github.com/lxn/walk/fontresource.go
2021-07-30 23:29:20 +01:00

84 lines
2.3 KiB
Go

// Copyright 2010 The Walk Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build windows
package walk
import (
"github.com/lxn/win"
"syscall"
)
// FontMemResource represents a font resource loaded into memory from
// the application's resources.
type FontMemResource struct {
hFontResource win.HANDLE
}
func newFontMemResource(resourceName *uint16) (*FontMemResource, error) {
hModule := win.HMODULE(win.GetModuleHandle(nil))
if hModule == win.HMODULE(0) {
return nil, lastError("GetModuleHandle")
}
hres := win.FindResource(hModule, resourceName, win.MAKEINTRESOURCE(8) /*RT_FONT*/)
if hres == win.HRSRC(0) {
return nil, lastError("FindResource")
}
size := win.SizeofResource(hModule, hres)
if size == 0 {
return nil, lastError("SizeofResource")
}
hResLoad := win.LoadResource(hModule, hres)
if hResLoad == win.HGLOBAL(0) {
return nil, lastError("LoadResource")
}
ptr := win.LockResource(hResLoad)
if ptr == 0 {
return nil, lastError("LockResource")
}
numFonts := uint32(0)
hFontResource := win.AddFontMemResourceEx(ptr, size, nil, &numFonts)
if hFontResource == win.HANDLE(0) || numFonts == 0 {
return nil, lastError("AddFontMemResource")
}
return &FontMemResource{hFontResource: hFontResource}, nil
}
// NewFontMemResourceByName function loads a font resource from the executable's resources
// using the resource name.
// The font must be embedded into resources using corresponding operator in the
// application's RC script.
func NewFontMemResourceByName(name string) (*FontMemResource, error) {
lpstr, err := syscall.UTF16PtrFromString(name)
if err != nil {
return nil, err
}
return newFontMemResource(lpstr)
}
// NewFontMemResourceById function loads a font resource from the executable's resources
// using the resource ID.
// The font must be embedded into resources using corresponding operator in the
// application's RC script.
func NewFontMemResourceById(id int) (*FontMemResource, error) {
return newFontMemResource(win.MAKEINTRESOURCE(uintptr(id)))
}
// Dispose removes the font resource from memory
func (fmr *FontMemResource) Dispose() {
if fmr.hFontResource != 0 {
win.RemoveFontMemResourceEx(fmr.hFontResource)
fmr.hFontResource = 0
}
}