enable virtual shift-mode button for IFR-1

Author: FloH

MobiFlight/Joysticks/Octavi/OctaviHandler.cs

@@ -6,6 +6,9 @@ namespace MobiFlight.Joysticks.Octavi
 {
     internal class OctaviHandler
     {
+        private const string Shift_VButton_Name = "Button_SHIFT_SW";
+        private const string Unshift_VButton_Name = "Button_UNSHIFT_SW";
+
         private bool isInShiftMode = false;
         private OctaviReport lastReport = new OctaviReport();
         private readonly List<string> buttons = new List<string>();
@@ -54,6 +57,16 @@ public OctaviHandler(JoystickDefinition definition = null)
                 var context = new Context(state, true, stateName + "^");
                 this.contexts.Add(context);
             }
+
+            /* create at least one instance for the Buttons for the virtual (un)shift events on context change.
+             * always created first to keep them together in the Button list.
+             * (shift button will only be called from the buttonmapping later,
+             * unshift either virtually without context or from the mapping)
+             */
+            _ = ToButton(Shift_VButton_Name);
+            _ = ToButton(Unshift_VButton_Name);
+
+
             foreach (var context in contexts)
             {
                 // Encoders
@@ -69,6 +82,22 @@ 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"));
+                    
+                    /* do not create the unshift button in the mapping, will be a duplicate key in the dictionary.
+                     * will be called with the buttons.IndexOf method later in this "virtual" case.
+                     */
+                    //buttonMappings.Add((context.state, context.isShifted, OctaviReport.OctaviButtons.HID_ENC_SW), ToButton(Unshift_VButton_Name));
+                }
+                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(context.isShifted ? Shift_VButton_Name : Unshift_VButton_Name));
                 }
 
                 // DCT, MENU, CLR, ENT, CDI, OBS, MSG, FLP, VNAV, PROC
@@ -86,6 +115,9 @@ 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)
@@ -137,10 +169,20 @@ 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/release)
+                int unshift_vButton = buttons.IndexOf(Unshift_VButton_Name);
+
+                if (unshift_vButton >= 0)
+                {
+                    buttonEvents.Add((unshift_vButton, MobiFlightButton.InputEvent.PRESS));
+                    buttonEvents.Add((unshift_vButton, MobiFlightButton.InputEvent.RELEASE));
+                }
+
+                isInShiftMode = false;
             }
             else if (pressed.HasFlag(OctaviReport.OctaviButtons.HID_ENC_SW) && this.definition.Inputs.Any(JoystickInput => JoystickInput.Id == (int)report.contextState))
             {
+                /* Button events will be generated by finding the corrensponding ButtonMapping in the loop at the end. */
                 isInShiftMode = !isInShiftMode;
             }