feat(gui): implement a loading panel with animation for AutoDev Planner #352

- Add a new LoadingPanel class to display loading messages with animation
- Integrate the LoadingPanel into the AutoDevPlannerToolWindow
- Implement typing animation for loading messages
- Update UI styling for the loading panel

Author: phodal

core/src/main/kotlin/cc/unitmesh/devti/gui/planner/AutoDevPlannerToolWindow.kt

@@ -16,9 +16,15 @@ import com.intellij.openapi.wm.ToolWindowManager
 import com.intellij.ui.dsl.builder.panel
 import com.intellij.util.ui.JBUI
 import com.intellij.util.ui.UIUtil
-import java.awt.BorderLayout
-import javax.swing.JLabel
-import javax.swing.JPanel
+import java.awt.*
+import java.awt.event.ActionEvent
+import java.awt.event.ActionListener
+import javax.swing.*
+import javax.swing.border.EmptyBorder
+import javax.swing.border.LineBorder
+import javax.swing.text.SimpleAttributeSet
+import javax.swing.text.StyleConstants
+import javax.swing.text.StyledDocument
 
 class AutoDevPlannerToolWindow(val project: Project) : SimpleToolWindowPanel(true, true), Disposable {
     override fun getName(): String = "AutoDev Planner"
@@ -50,6 +56,11 @@ class AutoDevPlannerToolWindow(val project: Project) : SimpleToolWindowPanel(tru
                 if (!isEditorMode && !isIssueInputMode) {
                     runInEdt {
                         planLangSketch.updatePlan(items)
+                        contentPanel.components.find { it is LoadingPanel }?.let {
+                            contentPanel.remove(it)
+                            contentPanel.revalidate()
+                            contentPanel.repaint()
+                        }
                     }
                 }
             }
@@ -156,10 +167,7 @@ class AutoDevPlannerToolWindow(val project: Project) : SimpleToolWindowPanel(tru
         contentPanel.removeAll()
         contentPanel.add(planPanel, BorderLayout.CENTER)
 
-        val loadingPanel = JPanel(BorderLayout()).apply {
-            add(JLabel("Processing your request..."), BorderLayout.NORTH)
-            background = JBUI.CurrentTheme.ToolWindow.background()
-        }
+        val loadingPanel = LoadingPanel(project)
         contentPanel.add(loadingPanel, BorderLayout.NORTH)
 
         contentPanel.revalidate()
@@ -176,7 +184,8 @@ class AutoDevPlannerToolWindow(val project: Project) : SimpleToolWindowPanel(tru
     companion object {
         fun showPlanEditor(project: Project, planText: String, callback: (String) -> Unit) {
             val toolWindow =
-                ToolWindowManager.Companion.getInstance(project).getToolWindow(AutoDevPlannerToolWindowFactory.Companion.PlANNER_ID)
+                ToolWindowManager.Companion.getInstance(project)
+                    .getToolWindow(AutoDevPlannerToolWindowFactory.Companion.PlANNER_ID)
             if (toolWindow != null) {
                 val content = toolWindow.contentManager.getContent(0)
                 val plannerWindow = content?.component as? AutoDevPlannerToolWindow
@@ -195,7 +204,8 @@ class AutoDevPlannerToolWindow(val project: Project) : SimpleToolWindowPanel(tru
 
         fun showIssueInput(project: Project) {
             val toolWindow = ToolWindowManager.Companion.getInstance(project).getToolWindow(
-                AutoDevPlannerToolWindowFactory.Companion.PlANNER_ID)
+                AutoDevPlannerToolWindowFactory.Companion.PlANNER_ID
+            )
             if (toolWindow == null) return
 
             val content = toolWindow.contentManager.getContent(0)
@@ -208,3 +218,94 @@ class AutoDevPlannerToolWindow(val project: Project) : SimpleToolWindowPanel(tru
         }
     }
 }
+
+private class LoadingPanel(project: Project) : JPanel(BorderLayout()) {
+    private val textPane = JTextPane()
+    private val timer = Timer(50, null)
+    private var currentText = ""
+    private var currentIndex = 0
+    private val loadingTexts = listOf(
+        "🤔 Analyzing your request...",
+        "💡 Generating a plan...",
+        "⚙️ Processing the steps...",
+        "✨ Almost there..."
+    )
+    private var currentTextIndex = 0
+
+    init {
+        background = JBUI.CurrentTheme.ToolWindow.background()
+        border = JBUI.Borders.empty(10)
+        preferredSize = Dimension(0, JBUI.scale(60))
+
+        val containerPanel = object : JPanel(BorderLayout()) {
+            override fun paintComponent(g: Graphics) {
+                super.paintComponent(g)
+                val g2d = g as Graphics2D
+                g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY)
+                g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON)
+
+                val gradient = GradientPaint(
+                    0f, 0f,
+                    JBUI.CurrentTheme.ToolWindow.background(),
+                    0f, height.toFloat(),
+                    JBUI.CurrentTheme.ToolWindow.background().darker()
+                )
+                g2d.paint = gradient
+                g2d.fillRect(0, 0, width, height)
+            }
+        }
+        containerPanel.border = LineBorder(UIUtil.getBoundsColor(), 1, true)
+        containerPanel.preferredSize = Dimension(0, JBUI.scale(50))
+
+        textPane.apply {
+            background = Color(0, 0, 0, 0)
+            foreground = UIUtil.getLabelForeground()
+            font = JBUI.Fonts.create("Monospaced", 14)
+            isEditable = false
+            isOpaque = false
+            border = JBUI.Borders.empty(10, 0)
+        }
+
+        containerPanel.add(textPane, BorderLayout.CENTER)
+        add(containerPanel, BorderLayout.CENTER)
+
+        startTypingAnimation()
+    }
+
+    private fun startTypingAnimation() {
+        timer.addActionListener(object : ActionListener {
+            override fun actionPerformed(e: ActionEvent) {
+                if (currentIndex < loadingTexts[currentTextIndex].length) {
+                    currentText += loadingTexts[currentTextIndex][currentIndex]
+                    updateText()
+                    currentIndex++
+                } else {
+                    currentIndex = 0
+                    currentText = ""
+                    currentTextIndex = (currentTextIndex + 1) % loadingTexts.size
+                }
+            }
+        })
+        timer.start()
+    }
+
+    private fun updateText() {
+        val doc = textPane.styledDocument
+        val style = SimpleAttributeSet()
+        StyleConstants.setForeground(style, UIUtil.getLabelForeground())
+        StyleConstants.setFontSize(style, 14)
+        StyleConstants.setFontFamily(style, "Monospaced")
+
+        try {
+            doc.remove(0, doc.length)
+            doc.insertString(0, currentText, style)
+        } catch (e: Exception) {
+            // Ignore any document modification errors
+        }
+    }
+
+    override fun removeNotify() {
+        super.removeNotify()
+        timer.stop()
+    }
+}