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// 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 size defines an event for the dimensions, physical resolution and
// orientation of the app's window.
//
// See the golang.org/x/mobile/app package for details on the event model.
package size // import "golang.org/x/mobile/event/size"
import (
"image"
"golang.org/x/mobile/geom"
)
// Event holds the dimensions, physical resolution and orientation of the app's
// window.
type Event struct {
// WidthPx and HeightPx are the window's dimensions in pixels.
WidthPx, HeightPx int
// WidthPt and HeightPt are the window's physical dimensions in points
// (1/72 of an inch).
//
// The values are based on PixelsPerPt and are therefore approximate, as
// per the comment on PixelsPerPt.
WidthPt, HeightPt geom.Pt
// PixelsPerPt is the window's physical resolution. It is the number of
// pixels in a single geom.Pt, from the golang.org/x/mobile/geom package.
//
// There are a wide variety of pixel densities in existing phones and
// tablets, so apps should be written to expect various non-integer
// PixelsPerPt values. In general, work in geom.Pt.
//
// The value is approximate, in that the OS, drivers or hardware may report
// approximate or quantized values. An N x N pixel square should be roughly
// 1 square inch for N = int(PixelsPerPt * 72), although different square
// lengths (in pixels) might be closer to 1 inch in practice. Nonetheless,
// this PixelsPerPt value should be consistent with e.g. the ratio of
// WidthPx to WidthPt.
PixelsPerPt float32
// Orientation is the orientation of the device screen.
Orientation Orientation
}
// Size returns the window's size in pixels, at the time this size event was
// sent.
func (e Event) Size() image.Point {
return image.Point{e.WidthPx, e.HeightPx}
}
// Bounds returns the window's bounds in pixels, at the time this size event
// was sent.
//
// The top-left pixel is always (0, 0). The bottom-right pixel is given by the
// width and height.
func (e Event) Bounds() image.Rectangle {
return image.Rectangle{Max: image.Point{e.WidthPx, e.HeightPx}}
}
// Orientation is the orientation of the device screen.
type Orientation int
const (
// OrientationUnknown means device orientation cannot be determined.
//
// Equivalent on Android to Configuration.ORIENTATION_UNKNOWN
// and on iOS to:
// UIDeviceOrientationUnknown
// UIDeviceOrientationFaceUp
// UIDeviceOrientationFaceDown
OrientationUnknown Orientation = iota
// OrientationPortrait is a device oriented so it is tall and thin.
//
// Equivalent on Android to Configuration.ORIENTATION_PORTRAIT
// and on iOS to:
// UIDeviceOrientationPortrait
// UIDeviceOrientationPortraitUpsideDown
OrientationPortrait
// OrientationLandscape is a device oriented so it is short and wide.
//
// Equivalent on Android to Configuration.ORIENTATION_LANDSCAPE
// and on iOS to:
// UIDeviceOrientationLandscapeLeft
// UIDeviceOrientationLandscapeRight
OrientationLandscape
)