Function windowConfigRead

app/android.go:185–239

(activity *C.ANativeActivity)

}

func windowConfigRead(activity *C.ANativeActivity) windowConfig {
	aconfig := C.AConfiguration_new()
	C.AConfiguration_fromAssetManager(aconfig, activity.assetManager)
	orient := C.AConfiguration_getOrientation(aconfig)
	density := C.AConfiguration_getDensity(aconfig)
	C.AConfiguration_delete(aconfig)

	// Calculate the screen resolution. This value is approximate. For example,
	// a physical resolution of 200 DPI may be quantized to one of the
	// ACONFIGURATION_DENSITY_XXX values such as 160 or 240.
	//
	// A more accurate DPI could possibly be calculated from
	// https://developer.android.com/reference/android/util/DisplayMetrics.html#xdpi
	// but this does not appear to be accessible via the NDK. In any case, the
	// hardware might not even provide a more accurate number, as the system
	// does not apparently use the reported value. See golang.org/issue/13366
	// for a discussion.
	var dpi int
	switch density {
	case C.ACONFIGURATION_DENSITY_DEFAULT:
		dpi = 160
	case C.ACONFIGURATION_DENSITY_LOW,
		C.ACONFIGURATION_DENSITY_MEDIUM,
		213, // C.ACONFIGURATION_DENSITY_TV
		C.ACONFIGURATION_DENSITY_HIGH,
		320, // ACONFIGURATION_DENSITY_XHIGH
		480, // ACONFIGURATION_DENSITY_XXHIGH
		640: // ACONFIGURATION_DENSITY_XXXHIGH
		dpi = int(density)
	case C.ACONFIGURATION_DENSITY_NONE:
		log.Print("android device reports no screen density")
		dpi = 72
	default:
		log.Printf("android device reports unknown density: %d", density)
		// All we can do is guess.
		if density > 0 {
			dpi = int(density)
		} else {
			dpi = 72
		}
	}

	o := size.OrientationUnknown
	switch orient {
	case C.ACONFIGURATION_ORIENTATION_PORT:
		o = size.OrientationPortrait
	case C.ACONFIGURATION_ORIENTATION_LAND:
		o = size.OrientationLandscape
	}

	return windowConfig{
		orientation: o,
		pixelsPerPt: float32(dpi) / 72,
	}
}

//export onConfigurationChanged
func onConfigurationChanged(activity *C.ANativeActivity) {