github.com/acrespo/mobile@v0.0.0-20190107162257-dc0771356504/event/mouse/mouse.go (about)

     1  // Copyright 2015 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Package mouse defines an event for mouse input.
     6  //
     7  // See the golang.org/x/mobile/app package for details on the event model.
     8  package mouse // import "golang.org/x/mobile/event/mouse"
     9  
    10  import (
    11  	"fmt"
    12  
    13  	"golang.org/x/mobile/event/key"
    14  )
    15  
    16  // Event is a mouse event.
    17  type Event struct {
    18  	// X and Y are the mouse location, in pixels.
    19  	X, Y float32
    20  
    21  	// Button is the mouse button being pressed or released. Its value may be
    22  	// zero, for a mouse move or drag without any button change.
    23  	Button Button
    24  
    25  	// TODO: have a field to hold what other buttons are down, for detecting
    26  	// drags or button-chords.
    27  
    28  	// Modifiers is a bitmask representing a set of modifier keys:
    29  	// key.ModShift, key.ModAlt, etc.
    30  	Modifiers key.Modifiers
    31  
    32  	// Direction is the direction of the mouse event: DirPress, DirRelease,
    33  	// or DirNone (for mouse moves or drags).
    34  	Direction Direction
    35  
    36  	// TODO: add a Device ID, for multiple input devices?
    37  	// TODO: add a time.Time?
    38  }
    39  
    40  // Button is a mouse button.
    41  type Button int32
    42  
    43  // IsWheel reports whether the button is for a scroll wheel.
    44  func (b Button) IsWheel() bool {
    45  	return b < 0
    46  }
    47  
    48  // TODO: have a separate axis concept for wheel up/down? How does that relate
    49  // to joystick events?
    50  
    51  const (
    52  	ButtonNone   Button = +0
    53  	ButtonLeft   Button = +1
    54  	ButtonMiddle Button = +2
    55  	ButtonRight  Button = +3
    56  
    57  	ButtonWheelUp    Button = -1
    58  	ButtonWheelDown  Button = -2
    59  	ButtonWheelLeft  Button = -3
    60  	ButtonWheelRight Button = -4
    61  )
    62  
    63  // Direction is the direction of the mouse event.
    64  type Direction uint8
    65  
    66  const (
    67  	DirNone    Direction = 0
    68  	DirPress   Direction = 1
    69  	DirRelease Direction = 2
    70  	// DirStep is a simultaneous press and release, such as a single step of a
    71  	// mouse wheel.
    72  	//
    73  	// Its value equals DirPress | DirRelease.
    74  	DirStep Direction = 3
    75  )
    76  
    77  func (d Direction) String() string {
    78  	switch d {
    79  	case DirNone:
    80  		return "None"
    81  	case DirPress:
    82  		return "Press"
    83  	case DirRelease:
    84  		return "Release"
    85  	case DirStep:
    86  		return "Step"
    87  	default:
    88  		return fmt.Sprintf("mouse.Direction(%d)", d)
    89  	}
    90  }