Add support for showing python version in tree view

.gitignore

@@ -1,4 +1,5 @@
 .gradle
 .idea
 .intellijPlatform
+.kotlin
 build

src/main/kotlin/com/github/pyvenvmanage/VenvProjectViewNodeDecorator.kt

@@ -0,0 +1,25 @@
+package com.github.pyvenvmanage
+
+import com.intellij.ide.projectView.PresentationData
+import com.intellij.ide.projectView.ProjectViewNode
+import com.intellij.ide.projectView.ProjectViewNodeDecorator
+import com.intellij.ui.SimpleTextAttributes
+
+import com.jetbrains.python.icons.PythonIcons.Python.Virtualenv
+
+class VenvProjectViewNodeDecorator : ProjectViewNodeDecorator {
+    override fun decorate(
+        node: ProjectViewNode<*>,
+        data: PresentationData,
+    ) {
+        val pyVenvCfgPath = VenvUtils.getPyVenvCfg(node.getVirtualFile())
+        if (pyVenvCfgPath != null) {
+            val pythonVersion = VenvUtils.getPythonVersionFromPyVenv(pyvenvCfgPath = pyVenvCfgPath)
+            val fileName: String? = data.getPresentableText()
+            data.clearText()
+            data.addText(fileName, SimpleTextAttributes.REGULAR_ATTRIBUTES)
+            data.addText(" [" + pythonVersion + "]", SimpleTextAttributes.GRAY_ATTRIBUTES)
+            data.setIcon(Virtualenv)
+        }
+    }
+}

src/main/kotlin/com/github/pyvenvmanage/VenvUtils.kt

@@ -0,0 +1,50 @@
+package com.github.pyvenvmanage
+
+import java.io.IOException
+import java.nio.charset.StandardCharsets
+import java.nio.file.Files
+import java.nio.file.Path
+import java.util.Properties
+
+import com.intellij.openapi.vfs.VirtualFile
+
+import com.jetbrains.python.sdk.PythonSdkUtil
+
+object VenvUtils {
+    @JvmStatic
+    fun getPyVenvCfg(file: VirtualFile?): Path? {
+        if (file != null && file.isDirectory()) {
+            val venvRootPath = file.getPath()
+            val pythonExecutable = PythonSdkUtil.getPythonExecutable(venvRootPath)
+            if (pythonExecutable != null) {
+                val pyvenvFile = file.findChild("pyvenv.cfg")
+                if (pyvenvFile != null) {
+                    return Path.of(pyvenvFile.getPath())
+                }
+            }
+        }
+        return null
+    }
+
+    @JvmStatic
+    fun getPythonVersionFromPyVenv(pyvenvCfgPath: Path): String {
+        val unknownVersion = "unknown"
+
+        val props = Properties()
+
+        try {
+            Files.newBufferedReader(pyvenvCfgPath, StandardCharsets.UTF_8).use { reader ->
+                props.load(reader)
+            }
+        } catch (e: IOException) {
+            return unknownVersion // file could not be read
+        }
+
+        val version = props.getProperty("version_info")
+        if (version != null) {
+            return version.trim { it <= ' ' }
+        }
+
+        return unknownVersion
+    }
+}

src/main/resources/META-INF/plugin.xml

@@ -7,9 +7,9 @@
     <depends>com.intellij.modules.platform</depends>
 
     <extensions defaultExtensionNs="com.intellij">
-        <notificationGroup id="Python SDK change" displayType="BALLOON"/>
-        <iconProvider implementation="com.github.pyvenvmanage.VenvIconProvider" />
-        <iconLayerProvider implementation="com.github.pyvenvmanage.VenvIconProvider" />
+        <notificationGroup id="SDK changed notification"
+                           displayType="BALLOON"/>
+        <projectViewNodeDecorator implementation="com.github.pyvenvmanage.VenvProjectViewNodeDecorator"/>
     </extensions>
 
     <actions>