add support for Flatpak's RemoteDesktop portal

README.md

@@ -3,7 +3,7 @@
 Control mouse and keyboard from the webbrowser of a smartphone (or any other device with a touchscreen).
 To take control open the displayed URL or scan the QR code.
 
-Supports Windows and X11.
+Supports Flatpak's RemoteDesktop portal (experimental), Windows and X11.
 
 ## Installation
 

desktop/remote-touchpad.appdata.xml

@@ -11,7 +11,7 @@
       To take control open the displayed URL or scan the QR code.
     </p>
     <p>
-      Supports Windows and X11.
+      Supports Flatpak&apos;s RemoteDesktop portal (experimental), Windows and X11.
     </p>
   </description>
   <url type="bugtracker">https://github.com/Unrud/remote-touchpad/issues</url>

flatpak/com.github.unrud.RemoteTouchpad.json

@@ -36,6 +36,12 @@
                     "commit" : "38087fe4dafb822e541b3f7955075cc1c30bd294",
                     "dest" : "src/github.com/elazarl/go-bindata-assetfs"
                 },
+                {
+                    "type" : "git",
+                    "url" : "https://anonscm.debian.org/git/pkg-go/packages/golang-dbus.git",
+                    "commit" : "79d96b151df08809558c825f8a75188826e8e228",
+                    "dest" : "src/anonscm.debian.org/git/pkg-go/packages/golang-dbus.git"
+                },
                 {
                     "type" : "git",
                     "path" : "..",
@@ -45,7 +51,7 @@
             ],
             "buildsystem" : "simple",
             "build-commands" : [
-                ". /usr/lib/sdk/golang/enable.sh; env GOPATH=\"$(pwd)\" go build -tags x11 github.com/unrud/remote-touchpad",
+                ". /usr/lib/sdk/golang/enable.sh; env GOPATH=\"$(pwd)\" go build -tags 'portal x11' github.com/unrud/remote-touchpad",
                 "install -Dm0755 -t /app/bin remote-touchpad",
                 "install -Dm0755 -t /app/bin src/github.com/unrud/remote-touchpad/desktop/remote-touchpad-wait-on-error",
                 "install -Dm0644 -t /app/share/appdata src/github.com/unrud/remote-touchpad/desktop/remote-touchpad.appdata.xml",

plugin.go

@@ -26,6 +26,7 @@ type PluginInfo struct {
 
 var Plugins []PluginInfo = []PluginInfo{
 	{"X11", InitX11Plugin},
+	{"RemoteDesktop portal", InitPortalPlugin},
 	{"Windows", InitWindowsPlugin},
 }
 

plugin_portal.go

@@ -0,0 +1,271 @@
+// +build portal
+
+/*
+ *    Copyright (c) 2018 Unrud<unrud@outlook.com>
+ *
+ *    This file is part of Remote-Touchpad.
+ *
+ *    Foobar is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    Remote-Touchpad is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with Foobar.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package main
+
+import (
+	dbus "anonscm.debian.org/git/pkg-go/packages/golang-dbus.git"
+	"errors"
+	"fmt"
+	"sync"
+)
+
+const (
+	deviceKeyboard uint32 = 1
+	devicePointer  uint32 = 2
+
+	btnReleased uint32 = 0
+	btnPressed  uint32 = 1
+
+	btnLeft   int32 = 0x110
+	btnRight  int32 = 0x111
+	btnMiddle int32 = 0x112
+)
+
+type portalPlugin struct {
+	bus           *dbus.Conn
+	remoteDesktop dbus.BusObject
+	sessionHandle dbus.ObjectPath
+	lock          sync.RWMutex
+}
+
+func InitPortalPlugin() (Plugin, error) {
+	bus, err := dbus.SessionBusPrivate()
+	if err != nil {
+		return nil, UnsupportedPlatformError{err}
+	}
+	cleanupBus := true
+	defer func() {
+		if cleanupBus {
+			bus.Close()
+		}
+	}()
+	err = bus.Auth(nil)
+	if err != nil {
+		return nil, UnsupportedPlatformError{err}
+	}
+	err = bus.Hello()
+	if err != nil {
+		return nil, UnsupportedPlatformError{err}
+	}
+	remoteDesktop := bus.Object("org.freedesktop.portal.Desktop",
+		"/org/freedesktop/portal/desktop")
+	availableDeviceTypesV, err := remoteDesktop.GetProperty(
+		"org.freedesktop.portal.RemoteDesktop.AvailableDeviceTypes")
+	if err != nil {
+		return nil, UnsupportedPlatformError{err}
+	}
+	availableDeviceTypes, ok := availableDeviceTypesV.Value().(uint32)
+	if !ok {
+		return nil, UnsupportedPlatformError{errors.New(
+			"unexpected 'AvailableDeviceTypes' return type")}
+	}
+	if availableDeviceTypes&deviceKeyboard == 0 ||
+		availableDeviceTypes&devicePointer == 0 {
+		return nil, UnsupportedPlatformError{errors.New(
+			"keyboard or pointer source type not supported")}
+	}
+	inVardict := make(map[string]dbus.Variant)
+	inVardict["session_handle_token"] = dbus.MakeVariant("t")
+	result, outVardict, err := getResponse(bus, remoteDesktop,
+		"org.freedesktop.portal.RemoteDesktop.CreateSession", 0, inVardict)
+	if err != nil {
+		return nil, UnsupportedPlatformError{err}
+	}
+	if result != 0 {
+		return nil, UnsupportedPlatformError{errors.New(fmt.Sprintf(
+			"Calling 'CreateSession' failed (%v)", result))}
+	}
+	sessionHandleV, ok := outVardict["session_handle"]
+	if !ok {
+		return nil, UnsupportedPlatformError{errors.New(
+			"'session_handle' missing from 'CreateSession' return value")}
+	}
+	sessionHandleS, ok := sessionHandleV.Value().(string)
+	if !ok {
+		return nil, UnsupportedPlatformError{errors.New(
+			"unexpected 'session_handle' type in 'CreateSession' return value")}
+	}
+	sessionHandle := dbus.ObjectPath(sessionHandleS)
+	inVardict = make(map[string]dbus.Variant)
+	inVardict["type"] = dbus.MakeVariant(deviceKeyboard | devicePointer)
+	result, outVardict, err = getResponse(bus, remoteDesktop,
+		"org.freedesktop.portal.RemoteDesktop.SelectDevices", 0, sessionHandle, inVardict)
+	if err != nil {
+		return nil, UnsupportedPlatformError{err}
+	}
+	if result != 0 {
+		return nil, UnsupportedPlatformError{errors.New(fmt.Sprintf(
+			"Calling 'SelectDevices' failed (%v)", result))}
+	}
+	inVardict = make(map[string]dbus.Variant)
+	result, outVardict, err = getResponse(bus, remoteDesktop,
+		"org.freedesktop.portal.RemoteDesktop.Start", 0, sessionHandle, "", inVardict)
+	if err != nil {
+		return nil, UnsupportedPlatformError{err}
+	}
+	if result != 0 {
+		return nil, errors.New("keyboard or pointer access denied")
+	}
+	devicesV, ok := outVardict["devices"]
+	if !ok {
+		return nil, UnsupportedPlatformError{errors.New(
+			"'devices' missing from 'Start' return value")}
+	}
+	devices, ok := devicesV.Value().(uint32)
+	if !ok {
+		return nil, UnsupportedPlatformError{errors.New(
+			"unexpected 'devices' type in 'Start' return value")}
+	}
+	if devices&deviceKeyboard == 0 || devices&devicePointer == 0 {
+		return nil, errors.New("keyboard or pointer access denied")
+	}
+	cleanupBus = false
+	return &portalPlugin{bus: bus, remoteDesktop: remoteDesktop,
+		sessionHandle: sessionHandle}, nil
+}
+
+func getResponse(bus *dbus.Conn, object dbus.BusObject, method string,
+	flags dbus.Flags, args ...interface{}) (uint32, map[string]dbus.Variant, error) {
+	ch := make(chan *dbus.Signal)
+	bus.Signal(ch)
+	defer bus.RemoveSignal(ch)
+	var requestPath dbus.ObjectPath
+	if err := object.Call(method, flags, args...).Store(&requestPath); err != nil {
+		return 0, nil, err
+	}
+	for {
+		s := <-ch
+		if s.Path == requestPath && s.Name == "org.freedesktop.portal.Request.Response" {
+			if len(s.Body) != 2 {
+				return 0, nil, errors.New("unexpected 'Response' return length")
+			}
+			result, ok := s.Body[0].(uint32)
+			if !ok {
+				return 0, nil, errors.New("unexpected 'Response' return type")
+			}
+			outVardict, ok := s.Body[1].(map[string]dbus.Variant)
+			if !ok {
+				return 0, nil, errors.New("unexpected 'Response' return type")
+			}
+			return result, outVardict, nil
+		}
+	}
+}
+
+func (p *portalPlugin) Close() error {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+	if p.bus == nil {
+		return errors.New("dbus connection closed")
+	}
+	if err := p.bus.Close(); err != nil {
+		return err
+	}
+	p.bus = nil
+	p.remoteDesktop = nil
+	return nil
+}
+
+func (p *portalPlugin) KeyboardText(text string) error {
+	p.lock.RLock()
+	defer p.lock.RUnlock()
+	if p.bus == nil {
+		return errors.New("dbus connection closed")
+	}
+	inVardict := make(map[string]dbus.Variant)
+	for _, runeValue := range text {
+		keysym := int32(0x01000000 + runeValue)
+		for _, state := range [...]uint32{btnPressed, btnReleased} {
+			if err := p.remoteDesktop.Call(
+				"org.freedesktop.portal.RemoteDesktop.NotifyKeyboardKeysym",
+				0, p.sessionHandle, inVardict, keysym, state).Store(); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (p *portalPlugin) PointerButton(button uint, press bool) error {
+	p.lock.RLock()
+	defer p.lock.RUnlock()
+	if p.bus == nil {
+		return errors.New("dbus connection closed")
+	}
+	var btn int32
+	if button == 1 {
+		btn = btnLeft
+	} else if button == 2 {
+		btn = btnMiddle
+	} else if button == 3 {
+		btn = btnRight
+	} else {
+		return errors.New("unsupported pointer button")
+	}
+	state := btnReleased
+	if press {
+		state = btnPressed
+	}
+	inVardict := make(map[string]dbus.Variant)
+	if err := p.remoteDesktop.Call("org.freedesktop.portal.RemoteDesktop.NotifyPointerButton",
+		0, p.sessionHandle, inVardict, btn, state).Store(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (p *portalPlugin) PointerMove(deltaX, deltaY int) error {
+	p.lock.RLock()
+	defer p.lock.RUnlock()
+	if p.bus == nil {
+		return errors.New("dbus connection closed")
+	}
+	inVardict := make(map[string]dbus.Variant)
+	if err := p.remoteDesktop.Call("org.freedesktop.portal.RemoteDesktop.NotifyPointerMotion",
+		0, p.sessionHandle, inVardict, float64(deltaX), float64(deltaY)).Store(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (p *portalPlugin) pointerScrollFull(deltaHorizontal, deltaVertical int, finish bool) error {
+	p.lock.RLock()
+	defer p.lock.RUnlock()
+	if p.bus == nil {
+		return errors.New("dbus connection closed")
+	}
+	inVardict := make(map[string]dbus.Variant)
+	inVardict["finish"] = dbus.MakeVariant(finish)
+	if err := p.remoteDesktop.Call("org.freedesktop.portal.RemoteDesktop.NotifyPointerAxis",
+		0, p.sessionHandle, inVardict, float64(deltaHorizontal), float64(deltaVertical)).Store(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (p *portalPlugin) PointerScroll(deltaHorizontal, deltaVertical int) error {
+	return p.pointerScrollFull(deltaHorizontal, deltaVertical, false)
+}
+
+func (p *portalPlugin) PointerScrollFinish() error {
+	return p.pointerScrollFull(0, 0, true)
+}

plugin_portal_dummy.go

@@ -0,0 +1,28 @@
+// +build !portal
+
+/*
+ *    Copyright (c) 2018 Unrud<unrud@outlook.com>
+ *
+ *    This file is part of Remote-Touchpad.
+ *
+ *    Foobar is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    Remote-Touchpad is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with Foobar.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package main
+
+import "errors"
+
+func InitPortalPlugin() (Plugin, error) {
+	return nil, UnsupportedPlatformError{errors.New("disabled")}
+}