enable virtual shift-mode button for IFR-1

Author: FloH

MobiFlight/Joysticks/Octavi/OctaviHandler.cs

@@ -54,6 +54,7 @@ public OctaviHandler(JoystickDefinition definition = null)
                 var context = new Context(state, true, stateName + "^");
                 this.contexts.Add(context);
             }
+
             foreach (var context in contexts)
             {
                 // Encoders
@@ -69,6 +70,18 @@ public OctaviHandler(JoystickDefinition definition = null)
                 if (!definition.Inputs.Any(JoystickInput => JoystickInput.Id == (int) context.state))
                 {
                     buttonMappings.Add((context.state, context.isShifted, OctaviReport.OctaviButtons.HID_ENC_SW), ToButton($"Button_{context.name}_CRSR"));
+                    buttonMappings.Add((context.state, context.isShifted, OctaviReport.OctaviButtons.HID_ENC_SW), ToButton($"Button_UNSHIFT_SW"));
+                }
+                else
+                {
+                    /* Will be used to raise the "we are shifted now" flag
+                    * Can be used to control a "shifted" variable that turns output pin 7 on/off
+                    * We need two buttons, because context switching forces "unshifting",
+                    * so the shift state always has to be sent explicitly
+                    * (i.e. not a variable that will be toggled when a single button is pressed can be used)
+                    * States that do not support a shift mode will always be "unshifted".
+                    */
+                    buttonMappings.Add((context.state, context.isShifted, OctaviReport.OctaviButtons.HID_ENC_SW), ToButton($"Button_{(context.isShifted ? "" : "UN")}SHIFT_SW"));
                 }
 
                 // DCT, MENU, CLR, ENT, CDI, OBS, MSG, FLP, VNAV, PROC
@@ -86,6 +99,9 @@ public OctaviHandler(JoystickDefinition definition = null)
                     buttonMappings.Add((context.state, context.isShifted, OctaviReport.OctaviButtons.HID_BTN_AP_ALT), ToButton($"Button_{context.name}_VNAV"));
                     buttonMappings.Add((context.state, context.isShifted, OctaviReport.OctaviButtons.HID_BTN_AP_VS), ToButton($"Button_{context.name}_PROC"));
                 }
+                /* else: why can't we use these buttons out of FMS-States?
+                 * e.g. Context COM1 Button -D-> could be used to set the radio to VATSIM Unicom "122.800"
+                 */
 
                 // AP, HDG, NAV, APR, ALT, VS (AP context only for now to not mess up the ordering of buttons)
                 if (context.state == OctaviReport.OctaviState.STATE_AP)
@@ -137,7 +153,14 @@ private int ToButton(string buttonName)
             // "Shift Mode" for supported contexts
             if (report.contextState != lastReport.contextState)
             {
-                isInShiftMode = false; // reset shift mode on context change
+                // reset shift mode on context changes (and synthesize unshift press)
+                if (buttonMappings.TryGetValue((lastReport.contextState, false, button), out int buttonIndex))
+                {
+                    var inputEvent = pressed.HasFlag(button) ? MobiFlightButton.InputEvent.PRESS : MobiFlightButton.InputEvent.RELEASE;
+                    buttonEvents.Add((buttonIndex, inputEvent));
+                }
+
+                isInShiftMode = false;
             }
             else if (pressed.HasFlag(OctaviReport.OctaviButtons.HID_ENC_SW) && this.definition.Inputs.Any(JoystickInput => JoystickInput.Id == (int)report.contextState))
             {