touch screen input

Signed-off-by: dignow <linlong1265@gmail.com>

flutter/lib/models/input_model.dart

@@ -268,6 +268,14 @@ class InputModel {
     sendMouse('up', button);
   }
 
+  void tapDown(MouseButtons button) {
+    sendMouse('down', button);
+  }
+
+    void tapUp(MouseButtons button) {
+    sendMouse('up', button);
+  }
+
   /// Send scroll event with scroll distance [y].
   void scroll(int y) {
     bind.sessionSendMouse(
@@ -429,7 +437,7 @@ class InputModel {
   }
 
   void onPointDownImage(PointerDownEvent e) {
-    debugPrint("onPointDownImage");
+    debugPrint("onPointDownImage ${e.kind}");
     _stopFling = true;
     if (e.kind != ui.PointerDeviceKind.mouse) {
       if (isPhysicalMouse.value) {
@@ -469,6 +477,7 @@ class InputModel {
       } else if (dy < 0) {
         dy = 1;
       }
+      debugPrint('REMOVE ME ================== onPointerSignalImage');
       bind.sessionSendMouse(
           sessionId: sessionId,
           msg: '{"type": "wheel", "x": "$dx", "y": "$dy"}');

flutter/lib/models/model.dart

@@ -1265,7 +1265,6 @@ class CursorModel with ChangeNotifier {
   }
 
   updatePan(double dx, double dy, bool touchMode) {
-    if (parent.target?.imageModel.image == null) return;
     if (touchMode) {
       final scale = parent.target?.canvasModel.scale ?? 1.0;
       _x += dx / scale;
@@ -1274,6 +1273,7 @@ class CursorModel with ChangeNotifier {
       notifyListeners();
       return;
     }
+    if (parent.target?.imageModel.image == null) return;
     final scale = parent.target?.canvasModel.scale ?? 1.0;
     dx /= scale;
     dy /= scale;