Made Type and ID private and added accessors for them.

src/ESPUIcontrol.h

@@ -7,54 +7,54 @@
 class Control
 {
 public:
-enum Type : uint8_t
-{
-    // fixed Controls
-    Title = 0,
+    enum Type : uint8_t
+    {
+        // fixed Controls
+        Title = 0,
 
-    // updatable Controls
-    Pad,
-    PadWithCenter,
-    Button,
-    Label,
-    Switcher,
-    Slider,
-    Number,
-    Text,
-    Graph,
-    GraphPoint,
-    Tab,
-    Select,
-    Option,
-    Min,
-    Max,
-    Step,
-    Gauge,
-    Accel,
-    Separator,
-    Time,
-    FileDisplay,
+        // updatable Controls
+        Pad,
+        PadWithCenter,
+        Button,
+        Label,
+        Switcher,
+        Slider,
+        Number,
+        Text,
+        Graph,
+        GraphPoint,
+        Tab,
+        Select,
+        Option,
+        Min,
+        Max,
+        Step,
+        Gauge,
+        Accel,
+        Separator,
+        Time,
+        FileDisplay,
 
-    Fragment = 98,
-    Password = 99,
-    UpdateOffset = 100,
-};
+        Fragment = 98,
+        Password = 99,
+        UpdateOffset = 100,
+    };
 
-enum Color : uint8_t
-{
-    Turquoise,
-    Emerald,
-    Peterriver,
-    Wetasphalt,
-    Sunflower,
-    Carrot,
-    Alizarin,
-    Dark,
-    None = 0xFF
-};
+    enum Color : uint8_t
+    {
+        Turquoise,
+        Emerald,
+        Peterriver,
+        Wetasphalt,
+        Sunflower,
+        Carrot,
+        Alizarin,
+        Dark,
+        None = 0xFF
+    };
+
+    typedef uint16_t ControlId_t;
 
-    Type type;
-    uint16_t id; // just mirroring the id here for practical reasons
     const char* label;
     std::function<void(Control*, int)> callback;
     String value;
@@ -63,15 +63,15 @@ enum Color : uint8_t
     bool wide;
     bool vertical;
     bool enabled;
-    uint16_t parentControl;
+    ControlId_t parentControl;
     String panelStyle;
     String elementStyle;
     String inputType;
-    Control* next;
 
     static constexpr uint16_t noParent = 0xffff;
 
-    Control(Type type,
+    Control(ControlId_t id,
+            Type type,
             const char* label,
             std::function<void(Control*, int)> callback,
             const String& value,
@@ -90,7 +90,8 @@ enum Color : uint8_t
     inline bool ToBeDeleted() { return _ToBeDeleted; }
     inline bool NeedsSync(uint32_t lastControlChangeID) {return (false == _ToBeDeleted) && (lastControlChangeID < ControlChangeID);}
     void    SetControlChangedId(uint32_t value) {ControlChangeID = value;}
-
+    inline ControlId_t GetId() {return id;}
+    inline Type        GetType() {return type;}
 
 #define UI_TITLE            Control::Type::Title
 #define UI_LABEL            Control::Type::Label
@@ -123,6 +124,9 @@ enum Color : uint8_t
 #define COLOR_NONE          Control::Color::None
 
 private:
+    Type type = Type::Title;
+    ControlId_t id = Control::noParent;
+
     bool _ToBeDeleted = false;
     uint32_t ControlChangeID = 0;
     String OldValue = emptyString;

src/ESPUIcontrolMgr.cpp

@@ -0,0 +1,371 @@
+
+#include "ESPUIControlMgr.h"
+
+static Control::ControlId_t idCounter = 0;
+
+_ESPUIcontrolMgr::_ESPUIcontrolMgr()
+{
+#ifdef ESP32
+    ControlsSemaphore = xSemaphoreCreateMutex();
+    xSemaphoreGive(ControlsSemaphore);
+#endif // def ESP32
+}
+
+void _ESPUIcontrolMgr::RemoveToBeDeletedControls()
+{
+#ifdef ESP32
+    xSemaphoreTake(ControlsSemaphore, portMAX_DELAY);
+#endif // def ESP32
+
+    ControlObject_t * PreviousControl = nullptr;
+    ControlObject_t * CurrentControl = controls;
+
+    while (nullptr != CurrentControl)
+    {
+        ControlObject_t * NextControl = CurrentControl->next;
+        if (CurrentControl->ToBeDeleted())
+        {
+            if (CurrentControl == controls)
+            {
+                // this is the root control
+                controls = NextControl;
+            }
+            else
+            {
+                PreviousControl->next = NextControl;
+            }
+            delete CurrentControl;
+            CurrentControl = NextControl;
+        }
+        else
+        {
+            PreviousControl = CurrentControl;
+            CurrentControl = NextControl;
+        }
+    }
+#ifdef ESP32
+    xSemaphoreGive(ControlsSemaphore);
+#endif // def ESP32
+}
+
+Control* _ESPUIcontrolMgr::getControl(Control::ControlId_t id)
+{
+#ifdef ESP32
+    xSemaphoreTake(ControlsSemaphore, portMAX_DELAY);
+#endif // !def ESP32
+    Control* Response = getControlNoLock(id);
+#ifdef ESP32
+    xSemaphoreGive(ControlsSemaphore);
+#endif // !def ESP32
+    return Response;
+}
+
+// WARNING: Anytime you walk the chain of controllers, the protection semaphore
+//          MUST be locked. This function assumes that the semaphore is locked
+//          at the time it is called. Make sure YOU locked it :)
+Control* _ESPUIcontrolMgr::getControlNoLock(Control::ControlId_t id)
+{
+    return getControlObjectNoLock(id);
+} // getControlNoLock
+
+// WARNING: Anytime you walk the chain of controllers, the protection semaphore
+//          MUST be locked. This function assumes that the semaphore is locked
+//          at the time it is called. Make sure YOU locked it :)
+_ESPUIcontrolMgr::ControlObject_t * _ESPUIcontrolMgr::getControlObjectNoLock(Control::ControlId_t id)
+{
+    ControlObject_t * Response = nullptr;
+    ControlObject_t * CurrentControl = controls;
+
+    while (nullptr != CurrentControl)
+    {
+        if (CurrentControl->GetId() == id)
+        {
+            if (!CurrentControl->ToBeDeleted())
+            {
+                Response = CurrentControl;
+            }
+            break;
+        }
+        CurrentControl = CurrentControl->next;
+    }
+
+    return Response;
+} // getControlObjectNoLock
+
+bool _ESPUIcontrolMgr::removeControl(Control::ControlId_t id)
+{
+    bool Response = false;
+
+    Control* control = getControl(id);
+    if (control)
+    {
+        Response = true;
+        control->DeleteControl();
+        controlCount--;
+    }
+#ifdef DEBUG_ESPUI
+    else
+    {
+        // Serial.println(String("Could not Remove Control ") + String(id));
+    }
+#endif // def DEBUG_ESPUI
+
+    return Response;
+}
+
+
+/*
+Prepare a chunk of elements as a single JSON string. If the allowed number of elements is greater than the total
+number this will represent the entire UI. More likely, it will represent a small section of the UI to be sent. The
+client will acknowledge receipt by requesting the next chunk.
+ */
+uint32_t _ESPUIcontrolMgr::prepareJSONChunk(uint16_t startindex,
+                                            JsonDocument & rootDoc,
+                                            bool InUpdateMode,
+                                            String FragmentRequestString,
+                                            uint32_t CurrentSyncID)
+{
+#ifdef ESP32
+    xSemaphoreTake(ControlsSemaphore, portMAX_DELAY);
+#endif // def ESP32
+
+    // Serial.println(String("prepareJSONChunk: Start.          InUpdateMode: ") + String(InUpdateMode));
+    // Serial.println(String("prepareJSONChunk: Start.            startindex: ") + String(startindex));
+    // Serial.println(String("prepareJSONChunk: Start. FragmentRequestString: '") + FragmentRequestString + "'");
+    int elementcount = 0;
+    uint32_t MaxMarshaledJsonSize = (!InUpdateMode) ? ESPUI.jsonInitialDocumentSize: ESPUI.jsonUpdateDocumentSize;
+    uint32_t EstimatedUsedMarshaledJsonSize = 0;
+
+    do // once
+    {
+        // Follow the list until control points to the startindex'th node
+        ControlObject_t * CurrentControlObject = controls;
+        uint32_t currentIndex = 0;
+        uint32_t DataOffset = 0;
+        JsonArray items = rootDoc[F("controls")];
+        bool SingleControl = false;
+
+        if(!emptyString.equals(FragmentRequestString))
+        {
+            // Serial.println(F("prepareJSONChunk:Fragmentation:Got Header (1)"));
+            // Serial.println(String("prepareJSONChunk:startindex:                  ") + String(startindex));
+            // Serial.println(String("prepareJSONChunk:currentIndex:                ") + String(currentIndex));
+            // Serial.println(String("prepareJSONChunk:FragmentRequestString:      '") + FragmentRequestString + "'");
+
+            // this is actually a fragment or directed update request
+            // parse the string we got from the UI and try to update that specific
+            // control.
+            AllocateJsonDocument(FragmentRequest, FragmentRequestString.length() * 3);
+/*
+            ArduinoJson::detail::sizeofObject(N);
+            if(0 >= FragmentRequest.capacity())
+            {
+                Serial.println(F("ERROR:prepareJSONChunk:Fragmentation:Could not allocate memory for a fragmentation request. Skipping Response"));
+                break;
+            }
+*/
+            size_t FragmentRequestStartOffset = FragmentRequestString.indexOf("{");
+            DeserializationError error = deserializeJson(FragmentRequest, FragmentRequestString.substring(FragmentRequestStartOffset));
+            if(DeserializationError::Ok != error)
+            {
+                Serial.println(F("ERROR:prepareJSONChunk:Fragmentation:Could not extract json from the fragment request"));
+                break;
+            }
+
+            if(!FragmentRequest.containsKey(F("id")))
+            {
+                Serial.println(F("ERROR:prepareJSONChunk:Fragmentation:Request does not contain a control ID"));
+                break;
+            }
+            uint16_t ControlId = uint16_t(FragmentRequest[F("id")]);
+
+            if(!FragmentRequest.containsKey(F("offset")))
+            {
+                Serial.println(F("ERROR:prepareJSONChunk:Fragmentation:Request does not contain a starting offset"));
+                break;
+            }
+            DataOffset = uint16_t(FragmentRequest[F("offset")]);
+            CurrentControlObject = getControlObjectNoLock(ControlId);
+            if(nullptr == CurrentControlObject)
+            {
+                Serial.println(String(F("ERROR:prepareJSONChunk:Fragmentation:Requested control: ")) + String(ControlId) + F(" does not exist"));
+                break;
+            }
+
+            // Serial.println(F("prepareJSONChunk:Fragmentation:disable the control search operation"));
+            currentIndex = 1;
+            startindex = 0;
+            SingleControl = true;
+        }
+
+        // find a control to send
+        while ((startindex > currentIndex) && (nullptr != CurrentControlObject))
+        {
+            // only count active controls
+            if (!CurrentControlObject->ToBeDeleted())
+            {
+                if(InUpdateMode)
+                {
+                    // In update mode we only count the controls that have been updated.
+                    if(CurrentControlObject->NeedsSync(CurrentSyncID))
+                    {
+                        ++currentIndex;
+                    }
+                }
+                else
+                {
+                    // not in update mode. Count all active controls
+                    ++currentIndex;
+                }
+            }
+            CurrentControlObject = CurrentControlObject->next;
+        }
+
+        // any controls left to be processed?
+        if(nullptr == CurrentControlObject)
+        {
+            // Serial.println("prepareJSONChunk: No controls to process");
+            break;
+        }
+
+        // keep track of the number of elements we have serialised into this
+        // message. Overflow is detected and handled later in this loop
+        // and needs an index to the last item added.
+        while (nullptr != CurrentControlObject)
+        {
+            // skip deleted controls or controls that have not been updated
+            if (CurrentControlObject->ToBeDeleted() && !SingleControl)
+            {
+                // Serial.println(String("prepareJSONChunk: Ignoring Deleted control: ") + String(control->id));
+                CurrentControlObject = CurrentControlObject->next;
+                continue;
+            }
+
+            if(InUpdateMode && !SingleControl)
+            {
+                if(CurrentControlObject->NeedsSync(CurrentSyncID))
+                {
+                    // dont skip this control
+                }
+                else
+                {
+                    // control has not been updated. Skip it
+                    CurrentControlObject = CurrentControlObject->next;
+                    continue;
+                }
+            }
+
+            // Serial.println(String(F("prepareJSONChunk: MaxMarshaledJsonSize: ")) + String(MaxMarshaledJsonSize));
+            // Serial.println(String(F("prepareJSONChunk: Cur EstimatedUsedMarshaledJsonSize: ")) + String(EstimatedUsedMarshaledJsonSize));
+
+            JsonObject item = AllocateJsonObject(items);
+            elementcount++;
+            uint32_t RemainingSpace = (MaxMarshaledJsonSize - EstimatedUsedMarshaledJsonSize) - 100;
+            // Serial.println(String(F("prepareJSONChunk: RemainingSpace: ")) + String(RemainingSpace));
+            uint32_t SpaceUsedByMarshaledControl = 0;
+            bool ControlIsFragmented = CurrentControlObject->MarshalControl(item,
+                                                               InUpdateMode,
+                                                               DataOffset,
+                                                               RemainingSpace,
+                                                               SpaceUsedByMarshaledControl);
+            // Serial.println(String(F("prepareJSONChunk: SpaceUsedByMarshaledControl: ")) + String(SpaceUsedByMarshaledControl));
+            EstimatedUsedMarshaledJsonSize += SpaceUsedByMarshaledControl;
+            // Serial.println(String(F("prepareJSONChunk: New EstimatedUsedMarshaledJsonSize: ")) + String(EstimatedUsedMarshaledJsonSize));
+            // Serial.println(String(F("prepareJSONChunk:                ControlIsFragmented: ")) + String(ControlIsFragmented));
+
+            // did the control get added to the doc?
+            if (0 == SpaceUsedByMarshaledControl ||
+                (ESPUI.jsonChunkNumberMax > 0 && (elementcount % ESPUI.jsonChunkNumberMax) == 0))
+            {
+                // Serial.println( String("prepareJSONChunk: too much data in the message. Remove the last entry"));
+                if (1 == elementcount)
+                {
+                    // Serial.println(String(F("prepareJSONChunk: Control ")) + String(control->id) + F(" is too large to be sent to the browser."));
+                    // Serial.println(String(F("ERROR: prepareJSONChunk: value: ")) + control->value);
+                    rootDoc.clear();
+                    item = AllocateJsonObject(items);
+                    CurrentControlObject->MarshalErrorMessage(item);
+                    elementcount = 0;
+                }
+                else
+                {
+                    // Serial.println(String("prepareJSONChunk: Defering control: ") + String(control->id));
+                    // Serial.println(String("prepareJSONChunk: elementcount: ") + String(elementcount));
+
+                    items.remove(elementcount);
+                    --elementcount;
+                }
+                // exit the loop
+                CurrentControlObject = nullptr;
+            }
+            else if ((SingleControl) ||
+                     (ControlIsFragmented) ||
+                     (MaxMarshaledJsonSize < (EstimatedUsedMarshaledJsonSize + 100)))
+            {
+                // Serial.println("prepareJSONChunk: Doc is Full, Fragmented Control or Single Control. exit loop");
+                CurrentControlObject = nullptr;
+            }
+            else
+            {
+                // Serial.println("prepareJSONChunk: Next Control");
+                CurrentControlObject = CurrentControlObject->next;
+            }
+        } // end while (control != nullptr)
+
+    } while (false);
+
+#ifdef ESP32
+    xSemaphoreGive(ControlsSemaphore);
+#endif // def ESP32
+
+    // Serial.println(String("prepareJSONChunk: END: elementcount: ") + String(elementcount));
+    return elementcount;
+}
+
+
+Control::ControlId_t _ESPUIcontrolMgr::addControl(Control::Type type,
+                                                  const char* label,
+                                                  const String& value,
+                                                  Control::Color color,
+                                                  Control::ControlId_t parentControl,
+                                                  bool visible,
+                                                  std::function<void(Control*, int)> callback)
+{
+    // Create a Wrapper and a control
+    ControlObject_t * NewControlObject  = new ControlObject_t(++idCounter, type, label, callback, value, color, visible, parentControl);
+    NewControlObject->next = nullptr;
+
+#ifdef ESP32
+    xSemaphoreTake(ControlsSemaphore, portMAX_DELAY);
+#endif // def ESP32
+
+    if (controls == nullptr)
+    {
+        controls = NewControlObject;
+    }
+    else
+    {
+        ControlObject_t * iterator = controls;
+        while (iterator->next != nullptr)
+        {
+            iterator = iterator->next;
+        }
+        iterator->next = NewControlObject;
+    }
+
+    controlCount++;
+
+#ifdef ESP32
+    xSemaphoreGive(ControlsSemaphore);
+#endif // def ESP32
+
+    return NewControlObject->GetId();
+}
+
+_ESPUIcontrolMgr::ControlObject_t::ControlObject_t(Control::ControlId_t id, Control::Type type, const char* label, std::function<void(Control*, int)> callback,
+    const String& value, Control::Color color, bool visible, ControlId_t parentControl)
+    : Control(id, type, label, callback, value, color, visible, parentControl)
+{}
+
+// Instantiate the singleton
+_ESPUIcontrolMgr ESPUIcontrolMgr;

src/ESPUIcontrolMgr.h

@@ -0,0 +1,62 @@
+#pragma once
+
+#include <Arduino.h>
+#include <ESPUI.h>
+#include <ESPUIControl.h>
+
+// implemented as a singleton
+class _ESPUIcontrolMgr
+{
+public:
+    _ESPUIcontrolMgr();
+    ~_ESPUIcontrolMgr() {}
+    _ESPUIcontrolMgr (_ESPUIcontrolMgr const&) = delete;
+    void operator=(_ESPUIcontrolMgr const&)  = delete;
+
+    Control::ControlId_t addControl(Control::Type type,
+                                    const char* label,
+                                    const String& value,
+                                    Control::Color color,
+                                    Control::ControlId_t parentControl,
+                                    bool visible,
+                                    std::function<void(Control*, int)> callback);
+    bool removeControl(Control::ControlId_t id);
+    void RemoveToBeDeletedControls();
+
+    Control* getControl(Control::ControlId_t id);
+    Control* getControlNoLock(Control::ControlId_t id);
+    Control::ControlId_t GetControlCount() {return controlCount;}
+
+    uint32_t prepareJSONChunk(uint16_t startindex,
+                              JsonDocument & rootDoc,
+                              bool InUpdateMode,
+                              String FragmentRequestString,
+                              uint32_t CurrentSyncID);
+private:
+    class ControlObject_t : public Control
+    {
+public:
+        ControlObject_t(Control::ControlId_t id,
+                        Type type,
+                        const char* label,
+                        std::function<void(Control*, int)> callback,
+                        const String& value,
+                        Color color,
+                        bool visible,
+                        uint16_t parentControl);
+
+        ControlObject_t * next = nullptr;
+    }; // ControlObject_t
+
+    ControlObject_t * controls = nullptr;
+    Control::ControlId_t controlCount = 0;
+    Control::ControlId_t idCounter = 0;
+    ControlObject_t * getControlObjectNoLock(Control::ControlId_t id);
+
+#ifdef ESP32
+    SemaphoreHandle_t ControlsSemaphore = NULL;
+#endif // def ESP32
+
+};
+
+extern _ESPUIcontrolMgr ESPUIcontrolMgr;