Example: A Simple UI Panel

PRO Example4_panel, wPanel, oUI 
 
   ; Set the title used on the panel's tab. 
   WIDGET_CONTROL, wPanel, BASE_SET_TITLE = 'Example Panel' 
 
   ; Specify the event handler 
   WIDGET_CONTROL, wPanel, EVENT_PRO = "Example4_panel_event" 
 
   ; Register the panel with the user interface object. 
   strObserverIdentifier = oUI->RegisterWidget(wPanel, "Panel", $ 
      'Example4_panel_callback') 
   ; Register to receive selection events on visualizations. 
   oUI->AddOnNotifyObserver, strObserverIdentifier, $ 
      'Visualization' 
    
   ; Retrieve a reference to the current iTool. 
   oTool = oUI->GetTool() 
 
   ; Create a base widget to hold the contents of the panel. 
   wBase = WIDGET_BASE(wPanel, /COLUMN, SPACE = 5, /ALIGN_LEFT) 
    
   ; Create panel contents. 
   wLabel = WIDGET_LABEL(wBase, VALUE = "Choose an Action:", $ 
      /ALIGN_LEFT) 
    
   ; Get the Operation ID of the rotate operation. If the operation 
   ; exists, create the "Rotate Item" button and monitor whether 
   ; the operation is available for the selected item. 
   opID = 'Operations/Operations/Rotate/RotateLeft' 
   oRotate = oTool->GetByIdentifier(opID) 
 
   IF (OBJ_VALID(oRotate)) THEN BEGIN 
      idRotate = oRotate->GetFullIdentifier() 
      wRotate = WIDGET_BUTTON(wBase, VALUE = "Rotate Item", $ 
         UVALUE="ROTATE") 
      ; Monitor for availablity of the Rotate operation. 
      oUI->AddOnNotifyObserver, strObserverIdentifier, idRotate 
   ENDIF ELSE $ 
      idRotate = 0 
 
   wHide = WIDGET_BUTTON(wBase, VALUE = "Show/Hide Item", $ 
      UVALUE = "HIDE") 
 
   ; Pack up the state structure and store in first child. 
   state = {oTool:oTool, $          
            oUI:oUI, $ 
            idRotate : idRotate, $ 
            wPanel:wPanel, $ 
            wBase:wBase, $ 
            wRotate:wRotate, $ 
            wHide:wHide $ 
          } 
   wChild = WIDGET_INFO(wPanel, /CHILD) 
 
   IF wChild NE 0 THEN $ 
      WIDGET_CONTROL, wChild, SET_UVALUE = state, /NO_COPY 
 
END 

PRO Example4_panel_event, event 
 
   ; Retrieve the widget ID of the first child widget of 
   ; the UI panel. 
   wChild = WIDGET_INFO(event.handler, /CHILD) 
 
   ; Retrieve the state structure from the user value of 
   ; the first child widget. 
   WIDGET_CONTROL, wChild, GET_UVALUE = state 
 
   ; Retrieve the user value of the widget that generated 
   ; the event. 
   WIDGET_CONTROL, event.id, GET_UVALUE = uvalue 
 
   ; Now do the work for each panel item. 
   SWITCH STRUPCASE(uvalue) OF 
      'ROTATE': BEGIN 
         ; Apply the Rotate Left operation to the selected item. 
         success = state.oUI->DoAction(state.idRotate) 
         RETURN 
      END 
      'HIDE': BEGIN 
         ; Hide the selected item. 
         ; 
         oTargets = state.oTool->GetSelectedItems(count = nTarg) 
         IF nTarg GT 0 THEN BEGIN 
            ; If there are selected items, use only the last item 
            ; selected, which is stored in the first element of 
            ; the returned array. 
            oTarget = oTargets[0] 
            ; Get the iTool identifier of the selected item. 
            name = oTarget->GetFullIdentifier() 
            ; Retrieve the setting of the HIDE property. 
            oTarget->GetProperty, HIDE = hide 
            ; Change the value of the HIDE property from 0 to 1 
            ; or from 1 to 0. Use the DoSetProperty and 
            ; CommitActions method to ensure that the change 
            ; is entered into the undo/redo transaction buffer. 
            void = state.oTool->DoSetProperty(name, "HIDE", $ 
               ((hide+1) MOD 2)) 
            state.oTool->CommitActions 
         ENDIF 
         BREAK 
      END 
      ELSE: 
   ENDSWITCH 
 
   ; Refresh the iTool window. 
   state.oTool->RefreshCurrentWindow 
 
END 

PRO Example4_panel_callback, wPanel, strID, messageIn, component 
 
   ; Make sure we have a valid widget ID. 
   IF ~ WIDGET_INFO(wPanel, /VALID) THEN RETURN 
 
   ; Retrieve the widget ID of the first child widget of 
   ; the UI panel. 
   wChild = WIDGET_INFO(wPanel, /CHILD) 
 
   ; Retrieve the state structure from the user value of 
   ; the first child widget. 
   WIDGET_CONTROL, wChild, GET_UVALUE = state 
    
   ; Process as necessary, depending on the message received. 
   SWITCH STRUPCASE(messageIn) OF 
    
      ; This section handles messages generated when the rotate 
      ; operation becomes available or unavailable, and sensitizes 
      ; or desensitizes the "Rotate" button accordingly. 
      'SENSITIVE': 
      'UNSENSITIVE': BEGIN 
         WIDGET_CONTROL, state.wRotate, $ 
            SENSITIVE = (messageIn EQ 'SENSITIVE') 
         BREAK 
      END 
 
      ; This section handles messages generated when the 
      ; item selected in the iTool window changes and changes 
      ; the sensitivity of the "Hide/Show" and "Rotate" buttons 
      ; accordingly. 
      'SELECTIONCHANGED': BEGIN 
         ; Retrieve the item that was selected last, which is 
         ; stored in the first element of the returned array. 
         oSel = state.oTool->GetSelectedItems() 
         oSel = oSel[0] 
         ; If the last item selected is not a visualization,  
         ; desensitize the "Hide/Show" and "Rotate" buttons. 
         IF (~OBJ_ISA(oSel, 'IDLITVISUALIZATION')) THEN BEGIN 
            WIDGET_CONTROL, state.wHide, SENSITIVE = 0 
            WIDGET_CONTROL, state.wRotate, SENSITIVE = 0 
         ENDIF ELSE BEGIN 
         ; If the selected object is a visualization, sensitize 
         ; the "Hide/Show" and "Rotate" buttons. 
            WIDGET_CONTROL, state.wHide, SENSITIVE = 1 
            WIDGET_CONTROL, state.wRotate, SENSITIVE = 1 
         ENDELSE 
         BREAK 
      END 
      ELSE: 
   ENDSWITCH 
    
END 

IREGISTER, 'Example Panel', 'Example4_panel', TYPE = 'EXAMPLE', $ 
   /UI_PANEL 

FUNCTION example4tool::Init, _REF_EXTRA = _extra 
 
IF (self->IDLitToolbase::Init(_EXTRA = _extra, $ 
                               TYPE = 'EXAMPLE') EQ 0) $ 
THEN RETURN, 0