TextureSelector: add option for disabling 'Load' entry

Allow plugins and PV based application to easily define a texture drop down list
programmatically.

Qt/Components/pqTextureComboBox.cxx

@@ -49,15 +49,17 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <QFileInfo>
 
 //-----------------------------------------------------------------------------
-pqTextureComboBox::pqTextureComboBox(vtkSMProxyGroupDomain* domain, QWidget* parent)
+pqTextureComboBox::pqTextureComboBox(vtkSMProxyGroupDomain* domain, bool canLoad, QWidget* parent)
   : Superclass(parent)
   , Domain(domain)
   , GroupName("")
+  , CanLoad(canLoad)
 {
   if (!this->Domain || this->Domain->GetNumberOfGroups() != 1)
   {
     qCritical() << "pqTextureSelectorPropertyWidget can only be used with a ProxyProperty"
                    " with a ProxyGroupDomain containing a single domain with a name.";
+    return;
   }
   else
   {
@@ -77,6 +79,12 @@ pqTextureComboBox::pqTextureComboBox(vtkSMProxyGroupDomain* domain, QWidget* par
     this, SLOT(proxyUnRegistered(const QString&, const QString&, vtkSMProxy*)));
 }
 
+//-----------------------------------------------------------------------------
+pqTextureComboBox::pqTextureComboBox(vtkSMProxyGroupDomain* domain, QWidget* parent)
+  : pqTextureComboBox(domain, true, parent)
+{
+}
+
 //-----------------------------------------------------------------------------
 void pqTextureComboBox::updateFromTexture(vtkSMProxy* texture)
 {
@@ -116,7 +124,10 @@ void pqTextureComboBox::updateTextures()
 
   this->clear();
   this->addItem("None", QVariant("NONE"));
-  this->addItem("Load ...", QVariant("LOAD"));
+  if (this->CanLoad)
+  {
+    this->addItem("Load ...", QVariant("LOAD"));
+  }
 
   for (unsigned int i = 0; i < this->Domain->GetNumberOfProxies(); i++)
   {
@@ -131,18 +142,18 @@ void pqTextureComboBox::updateTextures()
 //-----------------------------------------------------------------------------
 void pqTextureComboBox::onCurrentIndexChanged(int index)
 {
-  switch (index)
+  if (index == 0)
+  {
+    Q_EMIT textureChanged(nullptr);
+  }
+  else if (index == 1 && this->CanLoad)
+  {
+    this->loadTexture();
+  }
+  else
   {
-    case 0:
-      Q_EMIT textureChanged(nullptr);
-      break;
-    case 1:
-      this->loadTexture();
-      break;
-    default:
-      vtkSMProxy* texture = reinterpret_cast<vtkSMProxy*>(this->currentData().value<void*>());
-      Q_EMIT textureChanged(texture);
-      break;
+    vtkSMProxy* texture = reinterpret_cast<vtkSMProxy*>(this->currentData().value<void*>());
+    Q_EMIT textureChanged(texture);
   }
 }
 

Qt/Components/pqTextureComboBox.h

@@ -51,6 +51,7 @@ class PQCOMPONENTS_EXPORT pqTextureComboBox : public QComboBox
   typedef QComboBox Superclass;
 
 public:
+  pqTextureComboBox(vtkSMProxyGroupDomain* domain, bool canLoad, QWidget* parent = nullptr);
   pqTextureComboBox(vtkSMProxyGroupDomain* domain, QWidget* parent = nullptr);
   ~pqTextureComboBox() override = default;
 
@@ -83,6 +84,7 @@ private:
   vtkSMProxyGroupDomain* Domain;
   vtkNew<vtkEventQtSlotConnect> VTKConnector;
   QString GroupName;
+  bool CanLoad;
 };
 
 #endif

Qt/Components/pqTextureSelectorPropertyWidget.cxx

@@ -63,7 +63,18 @@ pqTextureSelectorPropertyWidget::pqTextureSelectorPropertyWidget(
 
   // Create the combobox selector and set its value
   auto* domain = smProperty->FindDomain<vtkSMProxyGroupDomain>();
-  this->Selector = new pqTextureComboBox(domain, this);
+  bool canLoad = true;
+  if (auto* hints = smProperty->GetHints())
+  {
+    auto* texHint = hints->FindNestedElementByName("TextureSelector");
+    QString attr = texHint ? texHint->GetAttributeOrEmpty("can_load_new") : "";
+    if (!attr.isEmpty())
+    {
+      canLoad = static_cast<bool>(attr.toInt());
+    }
+  }
+
+  this->Selector = new pqTextureComboBox(domain, canLoad, this);
   this->onPropertyChanged();
   l->addWidget(this->Selector);
   this->setLayout(l);

Utilities/Doxygen/pages/PropertyHints.md

@@ -308,3 +308,26 @@ The snippet below shows these hints in use.
           <HideResetButton/>
         </Hints>
     </DoubleVectorProperty>
+
+TextureSelectorPropertyWidget
+-------------------------------
+
+Customize the `pqTextureSelectorPropertyWidget` with the `TextureSelector` hint using the following attribute:
+
+* `can_load_new` - if 0 then user will not be able to load new texture from the drop down. Default to 1.
+
+The snippet below shows these hints in use.
+
+```xml
+<ProxyProperty command="SetTexture"
+                  name="Texture"
+                  panel_widget="texture_selector"
+                  null_on_empty="1" >
+    <ProxyGroupDomain name="groups">
+      <Group name="textures" />
+    </ProxyGroupDomain>
+    <Hints>
+      <TextureSelector can_load_new="0" />
+    </Hints>
+  </ProxyProperty>
+```