Adding upstream version 0.0~git20250520.a1d9079+dfsg.

Signed-off-by: Daniel Baumann <daniel@debian.org>

event/mouse/mouse.go

@@ -0,0 +1,90 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package mouse defines an event for mouse input.
+//
+// See the golang.org/x/mobile/app package for details on the event model.
+package mouse
+
+import (
+	"fmt"
+
+	"golang.org/x/mobile/event/key"
+)
+
+// Event is a mouse event.
+type Event struct {
+	// X and Y are the mouse location, in pixels.
+	X, Y float32
+
+	// Button is the mouse button being pressed or released. Its value may be
+	// zero, for a mouse move or drag without any button change.
+	Button Button
+
+	// TODO: have a field to hold what other buttons are down, for detecting
+	// drags or button-chords.
+
+	// Modifiers is a bitmask representing a set of modifier keys:
+	// key.ModShift, key.ModAlt, etc.
+	Modifiers key.Modifiers
+
+	// Direction is the direction of the mouse event: DirPress, DirRelease,
+	// or DirNone (for mouse moves or drags).
+	Direction Direction
+
+	// TODO: add a Device ID, for multiple input devices?
+	// TODO: add a time.Time?
+}
+
+// Button is a mouse button.
+type Button int32
+
+// IsWheel reports whether the button is for a scroll wheel.
+func (b Button) IsWheel() bool {
+	return b < 0
+}
+
+// TODO: have a separate axis concept for wheel up/down? How does that relate
+// to joystick events?
+
+const (
+	ButtonNone   Button = +0
+	ButtonLeft   Button = +1
+	ButtonMiddle Button = +2
+	ButtonRight  Button = +3
+
+	ButtonWheelUp    Button = -1
+	ButtonWheelDown  Button = -2
+	ButtonWheelLeft  Button = -3
+	ButtonWheelRight Button = -4
+)
+
+// Direction is the direction of the mouse event.
+type Direction uint8
+
+const (
+	DirNone    Direction = 0
+	DirPress   Direction = 1
+	DirRelease Direction = 2
+	// DirStep is a simultaneous press and release, such as a single step of a
+	// mouse wheel.
+	//
+	// Its value equals DirPress | DirRelease.
+	DirStep Direction = 3
+)
+
+func (d Direction) String() string {
+	switch d {
+	case DirNone:
+		return "None"
+	case DirPress:
+		return "Press"
+	case DirRelease:
+		return "Release"
+	case DirStep:
+		return "Step"
+	default:
+		return fmt.Sprintf("mouse.Direction(%d)", d)
+	}
+}