Make particle emitter editor window source code button disable itself is no source code is available

Source/Editor/Windows/Assets/ParticleEmitterWindow.cs

@@ -5,6 +5,7 @@ using System.Collections.Generic;
 using System.Linq;
 using FlaxEditor.Content;
 using FlaxEditor.CustomEditors;
+using FlaxEditor.GUI;
 using FlaxEditor.Scripting;
 using FlaxEditor.Surface;
 using FlaxEditor.Viewport.Previews;
@@ -114,6 +115,7 @@ namespace FlaxEditor.Windows.Assets
 
         private readonly PropertiesProxy _properties;
         private Tab _previewTab;
+        private ToolStripButton _showSourceCodeButton;
 
         /// <inheritdoc />
         public ParticleEmitterWindow(Editor editor, AssetItem item)
@@ -146,7 +148,8 @@ namespace FlaxEditor.Windows.Assets
 
             // Toolstrip
             SurfaceUtils.PerformCommonSetup(this, _toolstrip, _surface, out _saveButton, out _undoButton, out _redoButton);
-            _toolstrip.AddButton(editor.Icons.Code64, ShowSourceCode).LinkTooltip("Show generated shader source code");
+            _showSourceCodeButton = _toolstrip.AddButton(editor.Icons.Code64, ShowSourceCode);
+            _showSourceCodeButton.LinkTooltip("Show generated shader source code");
             _toolstrip.AddSeparator();
             _toolstrip.AddButton(editor.Icons.Docs64, () => Platform.OpenUrl(Utilities.Constants.DocsUrl + "manual/particles/index.html")).LinkTooltip("See documentation to learn more");
         }
@@ -285,5 +288,16 @@ namespace FlaxEditor.Windows.Assets
 
         /// <inheritdoc />
         public SearchAssetTypes AssetType => SearchAssetTypes.ParticleEmitter;
+    
+        /// <inheritdoc />
+        public override void Update(float deltaTime)
+        {
+            base.Update(deltaTime);
+
+            if(_asset == null)
+                return;
+
+            _showSourceCodeButton.Enabled = _asset.HasShaderCode();
+        }
     }
 }

Source/Engine/Particles/ParticleEmitter.cpp

@@ -440,4 +440,21 @@ bool ParticleEmitter::Save(const StringView& path)
     return SaveSurface(data);
 }
 
+bool ParticleEmitter::HasShaderCode()
+{
+    if(SimulationMode != ParticlesSimulationMode::GPU)
+    {
+        return false;
+    }
+
+    #if COMPILE_WITH_PARTICLE_GPU_GRAPH && COMPILE_WITH_SHADER_COMPILER
+    if(_shaderHeader.ParticleEmitter.GraphVersion == PARTICLE_GPU_GRAPH_VERSION
+        && HasChunk(SHADER_FILE_CHUNK_SOURCE)
+        && !HasDependenciesModified())
+        return true;
+    #endif
+
+    return false;
+}
+
 #endif

Source/Engine/Particles/ParticleEmitter.h

@@ -173,6 +173,12 @@ public:
 #if USE_EDITOR
     void GetReferences(Array<Guid>& assets, Array<String>& files) const override;
     bool Save(const StringView& path = StringView::Empty) override;
+
+    /// <summary>
+    /// Determine if the particle emitter has valid shader code present.
+    /// </summary>
+    /// <returns>True if particle emitter has shader code, otherwise false.</returns>
+    API_FUNCTION() bool HasShaderCode();
 #endif
 
 protected: