internal/ui: refactoring: separate the Windows API part to another file

internal/ui/api_windows.go

@@ -0,0 +1,99 @@
+// Copyright 2022 The Ebitengine Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !ebitenginecbackend && !ebitencbackend
+// +build !ebitenginecbackend,!ebitencbackend
+
+package ui
+
+import (
+	"fmt"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+const (
+	_SM_CYCAPTION             = 4
+	_MONITOR_DEFAULTTONEAREST = 2
+)
+
+type _RECT struct {
+	left   int32
+	top    int32
+	right  int32
+	bottom int32
+}
+
+type _MONITORINFO struct {
+	cbSize    uint32
+	rcMonitor _RECT
+	rcWork    _RECT
+	dwFlags   uint32
+}
+
+type _POINT struct {
+	x int32
+	y int32
+}
+
+var (
+	user32 = windows.NewLazySystemDLL("user32.dll")
+
+	procGetSystemMetrics  = user32.NewProc("GetSystemMetrics")
+	procMonitorFromWindow = user32.NewProc("MonitorFromWindow")
+	procGetMonitorInfoW   = user32.NewProc("GetMonitorInfoW")
+	procGetCursorPos      = user32.NewProc("GetCursorPos")
+)
+
+func _GetSystemMetrics(nIndex int) (int32, error) {
+	r, _, _ := procGetSystemMetrics.Call(uintptr(nIndex))
+	if int32(r) == 0 {
+		// GetLastError doesn't provide an extended information.
+		// See https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getsystemmetrics
+		return 0, fmt.Errorf("ui: GetSystemMetrics returned 0")
+	}
+	return int32(r), nil
+}
+
+func _MonitorFromWindow(hwnd windows.HWND, dwFlags uint32) uintptr {
+	r, _, _ := procMonitorFromWindow.Call(uintptr(hwnd), uintptr(dwFlags))
+	return r
+}
+
+func _GetMonitorInfoW(hMonitor uintptr) (_MONITORINFO, error) {
+	mi := _MONITORINFO{}
+	mi.cbSize = uint32(unsafe.Sizeof(mi))
+
+	r, _, e := procGetMonitorInfoW.Call(hMonitor, uintptr(unsafe.Pointer(&mi)))
+	if int32(r) == 0 {
+		if e != nil && e != windows.ERROR_SUCCESS {
+			return _MONITORINFO{}, fmt.Errorf("ui: GetMonitorInfoW failed: error code: %w", e)
+		}
+		return _MONITORINFO{}, fmt.Errorf("ui: GetMonitorInfoW failed: returned 0")
+	}
+	return mi, nil
+}
+
+func _GetCursorPos() (int32, int32, error) {
+	var pt _POINT
+	r, _, e := procGetCursorPos.Call(uintptr(unsafe.Pointer(&pt)))
+	if int32(r) == 0 {
+		if e != nil && e != windows.ERROR_SUCCESS {
+			return 0, 0, fmt.Errorf("ui: GetCursorPos failed: error code: %w", e)
+		}
+		return 0, 0, fmt.Errorf("ui: GetCursorPos failed: returned 0")
+	}
+	return pt.x, pt.y, nil
+}

internal/ui/ui_glfw_windows.go

@@ -21,7 +21,6 @@ import (
 	"errors"
 	"fmt"
 	"runtime"
-	"unsafe"
 
 	"golang.org/x/sys/windows"
 
@@ -63,80 +62,6 @@ func (*graphicsDriverCreatorImpl) newMetal() (graphicsdriver.Graphics, error) {
 	return nil, nil
 }
 
-const (
-	_SM_CYCAPTION             = 4
-	_MONITOR_DEFAULTTONEAREST = 2
-)
-
-type _RECT struct {
-	left   int32
-	top    int32
-	right  int32
-	bottom int32
-}
-
-type _MONITORINFO struct {
-	cbSize    uint32
-	rcMonitor _RECT
-	rcWork    _RECT
-	dwFlags   uint32
-}
-
-type _POINT struct {
-	x int32
-	y int32
-}
-
-var (
-	user32 = windows.NewLazySystemDLL("user32.dll")
-
-	procGetSystemMetrics  = user32.NewProc("GetSystemMetrics")
-	procMonitorFromWindow = user32.NewProc("MonitorFromWindow")
-	procGetMonitorInfoW   = user32.NewProc("GetMonitorInfoW")
-	procGetCursorPos      = user32.NewProc("GetCursorPos")
-)
-
-func _GetSystemMetrics(nIndex int) (int32, error) {
-	r, _, _ := procGetSystemMetrics.Call(uintptr(nIndex))
-	if int32(r) == 0 {
-		// GetLastError doesn't provide an extended information.
-		// See https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getsystemmetrics
-		return 0, fmt.Errorf("ui: GetSystemMetrics returned 0")
-	}
-	return int32(r), nil
-}
-
-func _MonitorFromWindow(hwnd windows.HWND, dwFlags uint32) uintptr {
-	r, _, _ := procMonitorFromWindow.Call(uintptr(hwnd), uintptr(dwFlags))
-	return r
-}
-
-func _GetMonitorInfoW(hMonitor uintptr) (_MONITORINFO, error) {
-	mi := _MONITORINFO{}
-	mi.cbSize = uint32(unsafe.Sizeof(mi))
-
-	r, _, e := procGetMonitorInfoW.Call(hMonitor, uintptr(unsafe.Pointer(&mi)))
-	if int32(r) == 0 {
-		if e != nil && e != windows.ERROR_SUCCESS {
-			return _MONITORINFO{}, fmt.Errorf("ui: GetMonitorInfoW failed: error code: %w", e)
-		}
-		return _MONITORINFO{}, fmt.Errorf("ui: GetMonitorInfoW failed: returned 0")
-	}
-	return mi, nil
-}
-
-func _GetCursorPos() (int32, int32, error) {
-	var pt _POINT
-	r, _, e := procGetCursorPos.Call(uintptr(unsafe.Pointer(&pt)))
-	if int32(r) == 0 {
-		if e != nil && e != windows.ERROR_SUCCESS {
-			return 0, 0, fmt.Errorf("ui: GetCursorPos failed: error code: %w", e)
-		}
-		return 0, 0, fmt.Errorf("ui: GetCursorPos failed: returned 0")
-	}
-	return pt.x, pt.y, nil
-}
-
 type userInterfaceImplNative struct {
 	origWindowPosX int
 	origWindowPosY int