8fffdfa9fd
Higher-level widget or animation libraries should probably work in geom.Pt, but pixels instead of (1/72s of) inches seems a better fit for lower-level event libraries. Needlessly converting from (float32) pixels to (float32) points and back can be lossy and lead to off-by-one errors. Change-Id: I68102e36f2574b07b44c6a1b7281f4f27f9174cf Reviewed-on: https://go-review.googlesource.com/13002 Reviewed-by: David Crawshaw <crawshaw@golang.org>
73 lines
1.9 KiB
Go
73 lines
1.9 KiB
Go
// Copyright 2015 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Package touch defines an event for touch input.
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//
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// See the golang.org/x/mobile/app package for details on the event model.
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package touch // import "golang.org/x/mobile/event/touch"
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// The best source on android input events is the NDK: include/android/input.h
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//
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// iOS event handling guide:
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// https://developer.apple.com/library/ios/documentation/EventHandling/Conceptual/EventHandlingiPhoneOS
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import (
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"fmt"
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)
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// Event is a touch event.
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type Event struct {
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// X and Y are the touch location, in pixels.
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X, Y float32
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// Sequence is the sequence number. The same number is shared by all events
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// in a sequence. A sequence begins with a single TypeBegin, is followed by
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// zero or more TypeMoves, and ends with a single TypeEnd. A Sequence
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// distinguishes concurrent sequences but its value is subsequently reused.
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Sequence Sequence
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// Type is the touch type.
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Type Type
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}
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// Sequence identifies a sequence of touch events.
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type Sequence int64
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// Type describes the type of a touch event.
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type Type byte
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const (
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// TypeBegin is a user first touching the device.
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//
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// On Android, this is a AMOTION_EVENT_ACTION_DOWN.
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// On iOS, this is a call to touchesBegan.
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TypeBegin Type = iota
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// TypeMove is a user dragging across the device.
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//
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// A TypeMove is delivered between a TypeBegin and TypeEnd.
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//
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// On Android, this is a AMOTION_EVENT_ACTION_MOVE.
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// On iOS, this is a call to touchesMoved.
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TypeMove
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// TypeEnd is a user no longer touching the device.
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//
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// On Android, this is a AMOTION_EVENT_ACTION_UP.
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// On iOS, this is a call to touchesEnded.
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TypeEnd
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)
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func (t Type) String() string {
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switch t {
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case TypeBegin:
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return "begin"
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case TypeMove:
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return "move"
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case TypeEnd:
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return "end"
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}
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return fmt.Sprintf("touch.Type(%d)", t)
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}
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