Fix canvas to display as empty when there is no source node input

Source/Plugins/LfpDisplayNodeAlpha/LfpDisplayCanvas.cpp

@@ -144,10 +144,18 @@ void LfpDisplayCanvas::resized()
     timescale->setBounds(leftmargin,0,getWidth()-scrollBarThickness-leftmargin,30);
     viewport->setBounds(0,30,getWidth(),getHeight()-90);
 
-    if (lfpDisplay->getSingleChannelState())
-        lfpDisplay->setChannelHeight(viewport->getHeight(),false);
-
-    lfpDisplay->setBounds(0,0,getWidth()-scrollBarThickness, lfpDisplay->getChannelHeight()*lfpDisplay->drawableChannels.size());
+    if (nChans > 0)
+    {
+        if (lfpDisplay->getSingleChannelState())
+            lfpDisplay->setChannelHeight(viewport->getHeight(),false);
+
+        std::cout << "number of channels " << nChans << std::endl;
+        lfpDisplay->setBounds(0,0,getWidth()-scrollBarThickness, lfpDisplay->getChannelHeight()*lfpDisplay->drawableChannels.size());
+    }
+    else
+    {
+        lfpDisplay->setBounds(0, 0, getWidth(), getHeight());
+    }
 
     if (optionsDrawerIsOpen)
         options->setBounds(0, getHeight()-200, getWidth(), 200);
@@ -197,14 +205,16 @@ void LfpDisplayCanvas::endAnimation()
 
 void LfpDisplayCanvas::update()
 {
-    nChans = jmax(processor->getNumInputs(),1);
+    nChans = jmax(processor->getNumInputs(), 0);
 
     resizeSamplesPerPixelBuffer(nChans);
 
     sampleRate.clear();
     screenBufferIndex.clear();
     lastScreenBufferIndex.clear();
     displayBufferIndex.clear();
+
+    options->setEnabled(nChans != 0);
 
     for (int i = 0; i <= nChans; i++) // extra channel for events
     {
@@ -256,9 +266,12 @@ void LfpDisplayCanvas::update()
             lfpDisplay->setEnabledState(isChannelEnabled[i], i);
 
         }
-
-        lfpDisplay->setBounds(0,0,getWidth()-scrollBarThickness*2, lfpDisplay->getTotalHeight());
-
+
+        if (nChans > 0)
+            lfpDisplay->setBounds(0,0,getWidth()-scrollBarThickness*2, lfpDisplay->getTotalHeight());
+        else
+            lfpDisplay->setBounds(0, 0, getWidth(), getHeight());
+
         resized();
     }
     else
@@ -271,7 +284,8 @@ void LfpDisplayCanvas::update()
 
     }
 
-    lfpDisplay->rebuildDrawableChannelsList();
+    if (nChans > 0)
+        lfpDisplay->rebuildDrawableChannelsList();
 
 }
 
@@ -1471,6 +1485,8 @@ void LfpDisplayOptions::setTimebaseAndSelectionText(float timebase)
 
 void LfpDisplayOptions::comboBoxChanged(ComboBox* cb)
 {
+    if (canvas->getNumChannels() == 0) return;
+
     if (cb == channelDisplaySkipSelection)
     {
         const int skipAmt = pow(2, cb->getSelectedId() - 1);

Source/Plugins/LfpDisplayNodeAlpha/LfpDisplayEditor.cpp

@@ -28,7 +28,7 @@ using namespace LfpDisplayNodeAlpha;
 
 LfpDisplayEditor::LfpDisplayEditor(GenericProcessor* parentNode, bool useDefaultParameterEditors=true)
     : VisualizerEditor(parentNode, useDefaultParameterEditors)
-
+, hasNoInputs(true)
 {
     lfpProcessor = (LfpDisplayNode*) parentNode;
     tabText = "LFP";
@@ -74,8 +74,8 @@ void LfpDisplayEditor::buttonClicked(Button *button)
         // (else) initialization errors. lots of time-critical cross dependencies here,
         // should be cleaned up
         updateSubprocessorSelectorOptions();
-        ((LfpDisplayCanvas *)canvas.get())->setDrawableSubprocessor(*(inputSubprocessorIndices.begin() + (subprocessorSelection->getSelectedId() - 1)));
-//        ((LfpDisplayCanvas*)canvas.get())->setDrawableSampleRate(*(inputSampleRates.begin() + (subprocessorSelection->getSelectedId() - 1)));
+        //((LfpDisplayCanvas *)canvas.get())->setDrawableSubprocessor(*(inputSubprocessorIndices.begin() + (subprocessorSelection->getSelectedId() - 1)));
+//        setCanvasDrawableSubprocessor(subprocessorSelection->getSelectedId() - 1);
 
         canvas->update();
 
@@ -110,6 +110,8 @@ void LfpDisplayEditor::updateSubprocessorSelectorOptions()
     inputSampleRates.clear();
     subprocessorSelection->clear(dontSendNotification);
 
+    hasNoInputs = lfpProcessor->getTotalDataChannels() != 0;
+
     for (int i = 0, len = lfpProcessor->getTotalDataChannels(); i < len; ++i)
     {
         int subProcessorIdx = lfpProcessor->getDataChannel(i)->getSubProcessorIdx();
@@ -142,13 +144,26 @@ void LfpDisplayEditor::updateSubprocessorSelectorOptions()
         subprocessorSampleRateLabel->setText(sampleRateLabelText, dontSendNotification);
         setCanvasDrawableSubprocessor(subprocessorToSet);
     }
+    else
+    {
+        subprocessorSelection->addItem ("None", 1);
+        subprocessorSelection->setSelectedId(1, dontSendNotification);
+
+        String sampleRateLabelText = "Sample Rate: <not available>";
+        subprocessorSampleRateLabel->setText(sampleRateLabelText, dontSendNotification);
+        setCanvasDrawableSubprocessor(-1);
+
+    }
 }
 
 void LfpDisplayEditor::setCanvasDrawableSubprocessor(int index)
 {
     if (canvas)
     {
-        ((LfpDisplayCanvas *)canvas.get())->setDrawableSubprocessor(*(inputSubprocessorIndices.begin() + index));
+        if (index >= 0)
+            ((LfpDisplayCanvas *)canvas.get())->setDrawableSubprocessor(*(inputSubprocessorIndices.begin() + index));
+        else
+            ((LfpDisplayCanvas *)canvas.get())->setDrawableSubprocessor(-1);
     }
 }
 

Source/Plugins/LfpDisplayNodeAlpha/LfpDisplayEditor.h

@@ -84,6 +84,8 @@ class LfpDisplayEditor : public VisualizerEditor,
 
     ScopedPointer<Label> subprocessorSampleRateLabel;
 
+    bool hasNoInputs;
+
     /** Communicates the drawable subprocessor information to the canvas, if
      one exists
      */