Support dynamic enabling and disabling of controls

See documentation in README for how this works. This commit
handles all the main controls. Pads are not yet supported.

README.md

@@ -37,6 +37,7 @@ The Library runs on any kind of **ESP8266** and **ESP32** (NodeMCU, AI Thinker,
 - [Advanced Features](#advanced-features)
   * [Dynamic Visibility](#dynamic-visibility)
   * [Inline Styles](#inline-styles)
+  * [Disabling Controls](#disabling-controls)
   * [Grouped controls](#grouped-controls)
   * [Wide controls](#wide-controls)
   * [Graph (Experimental)](#graph--experimental-)
@@ -470,6 +471,36 @@ The [completeExample](examples/completeExample/completeExample.cpp) example incl
 ![More Inline Styles](docs/ui_inlinestyles2.png)
 
 
+### Disabling Controls
+
+It is possible to dynamically enable and disable controls to, for example, provide feedback to the user that a particular feature is 
+temporarily unavailable. To do this use the following function call:
+
+```
+ESPUI.setEnabled(controlId, enabled);
+```
+
+Setting `enabled` to false will make the control noninteractive and it will visually change to illustrate this to the user. The control
+will stop firing any events. Note that whilst the widget will change appearance, the panel of the control will remain whatever colour 
+it was set to. If you wish to also change the colour of the panel then you should use inline styles to show the noninteractive state. For example:
+
+```
+ESPUI.setEnabled(mainButton, false);
+const String disabledstyle = "background-color: #bbb; border-bottom: #999 3px solid;";
+ESPUI.setPanelStyle(mainButton, disabledstyle);
+```
+
+This CSS style sets the panel background and its border to grey. To put the control back to enabled use the following:
+
+```
+ESPUI.setEnabled(mainButton, true);
+ESPUI.setPanelStyle(mainButton, ";");
+```
+
+Note that we have to set the inline style to `";"` (i.e. an empty CSS rule) because if we just try to set it to `""` this will be 
+interpreted as "do not change the style".
+
+Controls can also be set to disabled before the UI is started.
 
 ### Grouped controls
 

data/css/style.css

@@ -422,7 +422,7 @@ button {
   background-color: #999999;
 }
 
-button:active {
+button:enabled:active {
   background-color: #666666;
   transform: translateX(4px) translateY(4px);
 }
@@ -1148,3 +1148,46 @@ text {
 .vert-slider span {
   transform: rotate(90deg);
 }
+
+
+/* Styles to implement disabled controls */
+
+button:disabled {
+  color: #333;
+  background-color: #999;
+}
+
+select:disabled {
+  color: #333;
+  background-color: #999;
+}
+
+input:disabled {
+  color: #333;
+  background-color: #999;
+}
+
+.range-slider__range:disabled {
+  background-color: #999;
+}
+
+.range-slider__range:disabled::-webkit-slider-thumb {
+  background-color: #aaa;
+}
+
+.range-slider__range:disabled::-moz-range-thumb {
+  background-color: #aaa;
+}
+
+.switch.disabled .in::before {
+  background:#bbb;
+  border: 1px solid #ddd;
+}
+
+.switch.disabled .in::after {
+  background:#bbb;
+}
+
+.switch.checked.disabled {
+  background: #b1d092;
+}

data/js/controls.js

@@ -568,7 +568,13 @@ function start() {
         break;
     }
 
+    if (data.type >= UI_TITEL && data.type < UPDATE_OFFSET) {
+      //A UI element was just added to the DOM
+      processEnabled(data);
+    }
+
     if (data.type >= UPDATE_OFFSET && data.type < UI_INITIAL_GUI) {
+      //An "update" message was just recieved and processed
       var element = $("#id" + data.id);
 
       if(data.hasOwnProperty('panelStyle')) {
@@ -593,6 +599,8 @@ function start() {
         );
         element.addClass(colorClass(data.color));
       }
+
+      processEnabled(data);
     }
 
     $(".range-slider__range").each(function(){ 
@@ -817,3 +825,48 @@ var elementHTML = function(data) {
       return "";
   }
 }
+
+
+
+var processEnabled = function(data) {
+  //Handle the enabling and disabling of controls
+  //Most controls can be disabled through the use of $("#<item>").prop("disabled", true) and CSS will style it accordingly
+  //The switcher also requires the addition of the "disabled" class
+  switch(data.type) {
+    case UI_SWITCHER:
+    case UPDATE_SWITCHER:
+      if(data.enabled) {
+        $("#sl" + data.id).removeClass('disabled');
+        $("#s" + data.id).prop("disabled", false);
+      } else {
+        $("#sl" + data.id).addClass('disabled');
+        $("#s" + data.id).prop("disabled", true);
+      }
+      break;
+      
+    case UI_SLIDER:
+    case UPDATE_SLIDER:
+      $("#sl" + data.id).prop("disabled", !data.enabled);
+      break;
+
+    case UI_NUMBER:
+    case UPDATE_NUMBER:
+      $("#num" + data.id).prop("disabled", !data.enabled);
+      break;
+
+    case UI_TEXT_INPUT:
+    case UPDATE_TEXT_INPUT:
+      $("#text" + data.id).prop("disabled", !data.enabled);
+      break;
+    
+    case UI_SELECT:
+    case UPDATE_SELECT:
+      $("#select" + data.id).prop("disabled", !data.enabled);
+      break;
+
+    case UI_BUTTON:
+    case UPDATE_BUTTON:
+      $("#btn" + data.id).prop("disabled", !data.enabled);
+      break;
+  }
+}

data/js/controls.min.js

@@ -40,11 +40,13 @@ break;case UPDATE_SELECT:$("#select"+data.id).val(data.value);if(data.hasOwnProp
 break;case UPDATE_BUTTON:$("#btn"+data.id).val(data.value);$("#btn"+data.id).text(data.value);if(data.hasOwnProperty('elementStyle')){$("#btn"+data.id).attr("style",data.elementStyle);}
 break;case UPDATE_PAD:case UPDATE_CPAD:break;case UPDATE_GAUGE:$("#gauge"+data.id).val(data.value);if(data.hasOwnProperty('elementStyle')){$("#gauge"+data.id).attr("style",data.elementStyle);}
 break;case UPDATE_ACCEL:break;case UPDATE_TIME:var rv=new Date().toISOString();websock.send("time:"+rv+":"+data.id);break;default:console.error("Unknown type or event");break;}
+if(data.type>=UI_TITEL&&data.type<UPDATE_OFFSET){processEnabled(data);}
 if(data.type>=UPDATE_OFFSET&&data.type<UI_INITIAL_GUI){var element=$("#id"+data.id);if(data.hasOwnProperty('panelStyle')){$("#id"+data.id).attr("style",data.panelStyle);}
 if(data.hasOwnProperty('visible')){if(data['visible'])
 $("#id"+data.id).show();else
 $("#id"+data.id).hide();}
-if(data.type==UPDATE_SLIDER){element.removeClass("slider-turquoise slider-emerald slider-peterriver slider-wetasphalt slider-sunflower slider-carrot slider-alizarin");element.addClass("slider-"+colorClass(data.color));}else{element.removeClass("turquoise emerald peterriver wetasphalt sunflower carrot alizarin");element.addClass(colorClass(data.color));}}
+if(data.type==UPDATE_SLIDER){element.removeClass("slider-turquoise slider-emerald slider-peterriver slider-wetasphalt slider-sunflower slider-carrot slider-alizarin");element.addClass("slider-"+colorClass(data.color));}else{element.removeClass("turquoise emerald peterriver wetasphalt sunflower carrot alizarin");element.addClass(colorClass(data.color));}
+processEnabled(data);}
 $(".range-slider__range").each(function(){$(this)[0].value=$(this).attr("value");$(this).next().html($(this).attr("value"));});};websock.onmessage=handleEvent;}
 function sliderchange(number){var val=$("#sl"+number).val();websock.send("slvalue:"+val+":"+number);$(".range-slider__range").each(function(){$(this).attr("value",$(this)[0].value);});}
 function numberchange(number){var val=$("#num"+number).val();websock.send("nvalue:"+val+":"+number);}
@@ -95,3 +97,5 @@ data.value+"</span></div>";case UI_NUMBER:return"<input style='color:black;' "+e
 "' onchange='selectchange("+id+")' />";case UI_GRAPH:return"<figure id='graph"+id+"'><figcaption>"+data.label+"</figcaption></figure>";case UI_GAUGE:return"WILL BE A GAUGE <input style='color:black;' id='gauge"+id+
 "' type='number' value='"+data.value+"' onchange='numberchange("+id+")' />";case UI_ACCEL:return"ACCEL // Not implemented fully!<div class='accelerometer' id='accel"+id+
 "' ><div class='ball"+id+"'></div><pre class='accelerometeroutput"+id+"'></pre>";default:return"";}}
+var processEnabled=function(data){switch(data.type){case UI_SWITCHER:case UPDATE_SWITCHER:if(data.enabled){$("#sl"+data.id).removeClass('disabled');$("#s"+data.id).prop("disabled",false);}else{$("#sl"+data.id).addClass('disabled');$("#s"+data.id).prop("disabled",true);}
+break;case UI_SLIDER:case UPDATE_SLIDER:$("#sl"+data.id).prop("disabled",!data.enabled);break;case UI_NUMBER:case UPDATE_NUMBER:$("#num"+data.id).prop("disabled",!data.enabled);break;case UI_TEXT_INPUT:case UPDATE_TEXT_INPUT:$("#text"+data.id).prop("disabled",!data.enabled);break;case UI_SELECT:case UPDATE_SELECT:$("#select"+data.id).prop("disabled",!data.enabled);break;case UI_BUTTON:case UPDATE_BUTTON:$("#btn"+data.id).prop("disabled",!data.enabled);break;}}

src/ESPUI.cpp

@@ -783,6 +783,7 @@ void ESPUIClass::updateControl(Control* control, int clientId)
     root["id"] = control->id;
     root["visible"] = control->visible;
     root["color"] = (int)control->color;
+    root["enabled"] = control->enabled;
     if (control->panelStyle != 0)
         root["panelStyle"] = control->panelStyle;
     if (control->elementStyle != 0)
@@ -855,6 +856,16 @@ void ESPUIClass::setPanelWide(uint16_t id, bool wide) {
     }
 }
 
+void ESPUIClass::setEnabled(uint16_t id, bool enabled, int clientId) {
+    Control* control = getControl(id);
+    if (control)
+    {
+        control->enabled = enabled;
+        updateControl(control, clientId);
+    }
+}
+
+
 void ESPUIClass::setVertical(uint16_t id, bool vert) {
     Control* control = getControl(id);
     if (control)
@@ -1108,6 +1119,7 @@ void ESPUIClass::prepareJSONChunk(AsyncWebSocketClient* client, uint16_t startin
         item["value"] = String(control->value);
         item["color"] = (int)control->color;
         item["visible"] = (int)control->visible;
+        item["enabled"] = control->enabled;
         if (control->panelStyle != 0)
             item["panelStyle"] = String(control->panelStyle);
         if (control->elementStyle != 0)

src/ESPUI.h

@@ -142,6 +142,7 @@ public:
     bool visible;
     bool wide;
     bool vertical;
+    bool enabled;
     uint16_t parentControl;
     String panelStyle;
     String elementStyle;
@@ -301,6 +302,8 @@ public:
 
     void setPanelWide(uint16_t id, bool wide);
     void setVertical(uint16_t id, bool vert = true);
+    void setEnabled(uint16_t id, bool enabled = true, int clientId = -1);
+
     void updateVisibility(uint16_t id, bool visibility, int clientId = -1);
 
     // Variables