#5127: Another abstraction to allow for non-threaded populator implem…

…entations. The ResourceTreeView is planned to work with the IResourceTreePopulator only.

libs/wxutil/dataview/IResourceTreePopulator.h

@@ -0,0 +1,34 @@
+#pragma once
+
+#include "ResourceTreeView.h"
+
+namespace wxutil
+{
+
+/**
+ * TreeView populator interface, used to load data
+ * into a TreeModel instance used by ResourceTreeView.
+ * 
+ * It provides an interface to deal with threaded implementations:
+ * - Populate(): will at least start the population, might return
+ *               before or after the work is done.
+ * - EnsurePopulated(): will ensure that the population has been 
+ *                      started and will block until it's done.
+ */
+class IResourceTreePopulator
+{
+public:
+    using Ptr = std::shared_ptr<IResourceTreePopulator>;
+
+    virtual ~IResourceTreePopulator() {}
+
+    // Will start the population and block until population is done.
+    virtual void EnsurePopulated() = 0;
+
+    // Start the population process, unless it's already running
+    // This might spawn a worker thread which performs the
+    // population in the background - use EnsurePopulated to synchronise.
+    virtual void Populate() = 0;
+};
+
+}

libs/wxutil/dataview/ResourceTreeView.h

@@ -27,7 +27,7 @@ class ResourceTreeView :
     // The base structure defining a few needed default column.
     // Subclasses may derive from this struct to expand it
     struct Columns :
-        public wxutil::TreeModel::ColumnRecord
+        public TreeModel::ColumnRecord
     {
         Columns() :
             iconAndName(add(TreeModel::Column::IconText)),

libs/wxutil/dataview/ResourceTreePopulator.h → libs/wxutil/dataview/ThreadedResourceTreePopulator.h

@@ -3,16 +3,18 @@
 #include <wx/thread.h>
 #include <wx/event.h>
 #include "TreeModel.h"
+#include "IResourceTreePopulator.h"
 
 namespace wxutil
 {
 
 /**
- * Threaded helper class to load data into a ResourceTreeView.
+ * Threaded resource tree populator implementation class.
  * Subclasses need to implement the abstract members to add
  * the needed insertion or sorting logic.
  */
-class ResourceTreePopulator :
+class ThreadedResourceTreePopulator :
+    public IResourceTreePopulator,
     protected wxThread
 {
 private:
@@ -26,6 +28,9 @@ class ResourceTreePopulator :
     // updating the target tree store from a different thread isn't safe
     TreeModel::Ptr _treeStore;
 
+    // Whether this thread has been started at all
+    bool _started;
+
 protected:
 
     // Needed method to load data into the allocated tree model
@@ -60,38 +65,47 @@ class ResourceTreePopulator :
 
 public:
     // Construct and initialise variables
-    ResourceTreePopulator(const TreeModel::ColumnRecord& columns, wxEvtHandler* finishedHandler) :
+    ThreadedResourceTreePopulator(const TreeModel::ColumnRecord& columns, wxEvtHandler* finishedHandler) :
         wxThread(wxTHREAD_JOINABLE),
         _finishedHandler(finishedHandler),
-        _columns(columns)
+        _columns(columns),
+        _started(false)
     {}
 
-    ~ResourceTreePopulator()
+    ~ThreadedResourceTreePopulator()
     {
-        if (IsRunning())
+        if (IsAlive())
         {
             Delete(); // cancel the running thread
         }
     }
 
     // Blocks until the worker thread is done. 
-    // Returns immediately if the thread is not running
-    void WaitUntilFinished()
+    void EnsurePopulated() override
     {
+        // Start the thread now if we have to
+        if (!_started)
+        {
+            Populate();
+        }
+
+        // Wait for any running thread
         if (IsRunning())
         {
             Wait();
         }
     }
 
     // Start the thread, if it isn't already running
-    void Run()
+    void Populate() override
     {
         if (IsRunning())
         {
             return;
         }
 
+        // Set the latch
+        _started = true;
         wxThread::Run();
     }
 };

radiant/ui/mediabrowser/MediaBrowserTreeView.cpp

@@ -161,7 +161,7 @@ struct ShaderNameFunctor
 };
 
 class Populator :
-    public wxutil::ResourceTreePopulator
+    public wxutil::ThreadedResourceTreePopulator
 {
 private:
     const MediaBrowserTreeView::TreeColumns& _columns;
@@ -172,7 +172,7 @@ class Populator :
 public:
     // Construct and initialise variables
     Populator(const MediaBrowserTreeView::TreeColumns& columns, wxEvtHandler* finishedHandler) :
-        ResourceTreePopulator(columns, finishedHandler),
+        ThreadedResourceTreePopulator(columns, finishedHandler),
         _columns(columns)
     {
         _favourites = GlobalFavouritesManager().getFavourites(decl::Type::Material);
@@ -315,7 +315,7 @@ void MediaBrowserTreeView::populate()
 
     // Start the background thread
     _populator.reset(new Populator(_columns, this));
-    _populator->Run();
+    _populator->Populate();
 }
 
 void MediaBrowserTreeView::clear()
@@ -334,13 +334,8 @@ void MediaBrowserTreeView::_onTreeStorePopulationFinished(wxutil::TreeModel::Pop
 
 void MediaBrowserTreeView::setSelection(const std::string& fullName)
 {
-    if (!_isPopulated)
-    {
-        populate();
-    }
-
-    // Make sure the treestore is finished loading
-    _populator->WaitUntilFinished();
+    // Make sure the treestore is loaded
+    _populator->EnsurePopulated();
 
     ResourceTreeView::setSelection(fullName);
 }

radiant/ui/mediabrowser/MediaBrowserTreeView.h

@@ -1,7 +1,7 @@
 #pragma once
 
 #include "wxutil/dataview/ResourceTreeView.h"
-#include "wxutil/dataview/ResourceTreePopulator.h"
+#include "wxutil/dataview/ThreadedResourceTreePopulator.h"
 #include "wxutil/menu/IconTextMenuItem.h"
 #include "wxutil/dataview/TreeModelFilter.h"
 
@@ -25,7 +25,7 @@ class MediaBrowserTreeView :
 
 private:
     // Populates the Media Browser in its own thread
-    std::unique_ptr<wxutil::ResourceTreePopulator> _populator;
+    std::unique_ptr<wxutil::ThreadedResourceTreePopulator> _populator;
 
     // false, if the tree is not yet initialised.
     bool _isPopulated;

tools/msvc/wxutillib.vcxproj

@@ -139,9 +139,10 @@
     <ClInclude Include="..\..\libs\wxutil\ChoiceHelper.h" />
     <ClInclude Include="..\..\libs\wxutil\ConsoleView.h" />
     <ClInclude Include="..\..\libs\wxutil\ControlButton.h" />
+    <ClInclude Include="..\..\libs\wxutil\dataview\IResourceTreePopulator.h" />
     <ClInclude Include="..\..\libs\wxutil\dataview\KeyValueTable.h" />
-    <ClInclude Include="..\..\libs\wxutil\dataview\ResourceTreePopulator.h" />
     <ClInclude Include="..\..\libs\wxutil\dataview\ResourceTreeView.h" />
+    <ClInclude Include="..\..\libs\wxutil\dataview\ThreadedResourceTreePopulator.h" />
     <ClInclude Include="..\..\libs\wxutil\dataview\TreeModel.h" />
     <ClInclude Include="..\..\libs\wxutil\dataview\TreeModelFilter.h" />
     <ClInclude Include="..\..\libs\wxutil\dataview\TreeView.h" />

tools/msvc/wxutillib.vcxproj.filters

@@ -133,7 +133,10 @@
     <ClInclude Include="..\..\libs\wxutil\dataview\VFSTreePopulator.h">
       <Filter>dataview</Filter>
     </ClInclude>
-    <ClInclude Include="..\..\libs\wxutil\dataview\ResourceTreePopulator.h">
+    <ClInclude Include="..\..\libs\wxutil\dataview\IResourceTreePopulator.h">
+      <Filter>dataview</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\libs\wxutil\dataview\ThreadedResourceTreePopulator.h">
       <Filter>dataview</Filter>
     </ClInclude>
   </ItemGroup>