[collab/space] IDEA-326214: New design of review details panel

Merge-request: IJ-MR-135612 Merged-by: Alexander Zamyshlyaev <Alexander.Zamyshlyaev@jetbrains.com> GitOrigin-RevId: 28b68d869e364a2b04b4dee45fe2aa88fd4741d6
2026-03-22 15:19:59 +07:00 · 2024-06-10 15:24:25 +00:00
parent d69e825ddb
commit 94280c45e9
1 changed files with 176 additions and 0 deletions
--- a/platform/collaboration-tools/src/com/intellij/collaboration/ui/ScrollPaneWithStickyHeaders.kt
+++ b/platform/collaboration-tools/src/com/intellij/collaboration/ui/ScrollPaneWithStickyHeaders.kt
@@ -0,0 +1,176 @@
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.collaboration.ui
+
+import com.intellij.openapi.ui.OnePixelDivider
+import com.intellij.openapi.ui.VerticalFlowLayout
+import com.intellij.ui.IdeBorderFactory
+import com.intellij.ui.SideBorder
+import com.intellij.ui.components.JBLayeredPane
+import com.intellij.ui.components.JBScrollPane
+import com.intellij.ui.components.panels.NonOpaquePanel
+import com.intellij.ui.components.panels.OpaquePanel
+import com.intellij.util.ui.JBUI
+import org.jetbrains.annotations.ApiStatus.Internal
+import java.awt.BorderLayout
+import java.awt.Component
+import java.awt.event.MouseAdapter
+import java.awt.event.MouseEvent
+import javax.swing.JComponent
+import javax.swing.JPanel
+
+@Internal
+object ScrollPaneWithStickyHeaders {
+  /**
+   * @param components List of child components along with sticky flags
+   */
+  fun create(components: List<Pair<JComponent, Boolean>>): JComponent {
+    val stickyLayer = NonOpaquePanel(BorderLayout())
+
+    val topStickedPane = OpaquePanel(VerticalFlowLayout(0, 0)).apply {
+      border = IdeBorderFactory.createBorder(OnePixelDivider.BACKGROUND, SideBorder.BOTTOM)
+    }
+
+    val bottomStickedPane = OpaquePanel(VerticalFlowLayout(0, 0)).apply {
+      border = IdeBorderFactory.createBorder(OnePixelDivider.BACKGROUND, SideBorder.BOTTOM)
+    }
+
+    val scrolledBody = NonOpaquePanel(VerticalFlowLayout(0, 0))
+
+    val scrollPane = JBScrollPane(scrolledBody)
+
+    val stickyElements = mutableMapOf<Component, StickyElement>()
+    var prevElement: StickyElement? = null
+
+    components.forEach { (component, isSticky) ->
+
+      if (isSticky) {
+        val (wrapper, element) = addStickySection(scrolledBody, topStickedPane, bottomStickedPane, component)
+        stickyElements[wrapper] = element
+        prevElement?.apply { nextElem = element }
+        prevElement = element
+      }
+      else scrolledBody.add(component)
+    }
+
+    return JBLayeredPane().apply {
+      name = "scrollable-sticked-pane"
+      isFullOverlayLayout = true
+      scrollPane.border = JBUI.Borders.empty()
+
+      scrollPane.viewport.addChangeListener {
+        val position = scrollPane.viewport.viewPosition
+        val topMargin = topStickedPane.height
+        val bottomMargin = bottomStickedPane.height
+
+        scrolledBody.components.mapNotNull { stickyElements[it] }
+          .forEach { elem ->
+            var topLimit = position.y + topMargin
+            if (elem.isInTop) topLimit -= elem.wrapperBody.height
+
+            var bottomLimit = position.y + scrollPane.height - bottomMargin
+            if (elem.isInBottom) bottomLimit += elem.wrapperBody.height - (elem.nextElem?.wrapperBody?.height ?: 0)
+
+            elem.underTopLimit = elem.wrapperBody.y > topLimit
+            elem.aboveBottomLimit = elem.wrapperBody.y + elem.wrapperBody.height < bottomLimit
+
+            elem.move()
+            applyBottomConstraint(bottomStickedPane)
+
+            revalidate()
+            repaint()
+          }
+      }
+
+      stickyLayer.add(topStickedPane, BorderLayout.NORTH)
+      stickyLayer.add(bottomStickedPane, BorderLayout.SOUTH)
+
+      add(stickyLayer, 1 as Any)
+      add(scrollPane, 0 as Any)
+    }
+  }
+
+  private fun addStickySection(scrolledBody: JPanel, topStickedPane: JPanel, bottomStickedPane: JPanel, comp: JComponent):
+    Pair<JComponent, StickyElement> {
+
+    val wrapperInBody = OpaquePanel(BorderLayout())
+    wrapperInBody.border = IdeBorderFactory.createBorder(OnePixelDivider.BACKGROUND, SideBorder.TOP)
+    wrapperInBody.add(comp)
+    scrolledBody.add(wrapperInBody)
+
+    val wrapperInTop = NonOpaquePanel(BorderLayout())
+    wrapperInTop.border = IdeBorderFactory.createBorder(OnePixelDivider.BACKGROUND, SideBorder.TOP)
+    topStickedPane.add(wrapperInTop)
+    val wrapperInBottom = NonOpaquePanel(BorderLayout())
+    wrapperInBottom.border = IdeBorderFactory.createBorder(OnePixelDivider.BACKGROUND, SideBorder.TOP)
+    bottomStickedPane.add(wrapperInBottom)
+
+    return wrapperInBody to StickyElement(
+      comp,
+      wrapperInBody,
+      wrapperInTop,
+      wrapperInBottom,
+      scrolledBody
+    )
+  }
+
+  private fun applyBottomConstraint(bottomStickedPane: JPanel) {
+    val populated = bottomStickedPane.components.filter { (it as JPanel).componentCount > 0 }
+    populated.firstOrNull()?.isVisible = true
+    populated.drop(1).forEach { it.isVisible = false }
+  }
+
+  private class StickyElement(
+    val component: Component,
+    val wrapperBody: JPanel,
+    val wrapperTop: JPanel,
+    val wrapperBottom: JPanel,
+    scrolledBody: JPanel,
+  ) {
+    var underTopLimit = true
+    var aboveBottomLimit = true
+    var nextElem: StickyElement? = null
+
+    val isInTop get() = wrapperTop.componentCount > 0
+    val isInBottom get() = wrapperBottom.componentCount > 0
+    val isInBody get() = !isInTop && !isInBottom
+
+    /** Used to reserve space in the scrollable body when the component is not there */
+    private val dummy = NonOpaquePanel()
+
+    init {
+      wrapperTop.addMouseListener(object : MouseAdapter() {
+        override fun mouseClicked(e: MouseEvent) {
+          scrolledBody.scrollRectToVisible(wrapperBody.bounds)
+        }
+      })
+      wrapperBottom.addMouseListener(object : MouseAdapter() {
+        override fun mouseClicked(e: MouseEvent) {
+          scrolledBody.scrollRectToVisible(wrapperBody.bounds)
+        }
+      })
+    }
+
+    fun move() {
+      when {
+        !underTopLimit && !isInTop -> {
+          wrapperTop.add(component)
+          wrapperTop.isVisible = true
+          dummy.preferredSize = component.preferredSize
+          wrapperBody.add(dummy)
+        }
+        underTopLimit && aboveBottomLimit && !isInBody -> {
+          wrapperTop.isVisible = false
+          wrapperBottom.isVisible = false
+          wrapperBody.remove(dummy)
+          wrapperBody.add(component)
+        }
+        !aboveBottomLimit && !isInBottom -> {
+          wrapperBottom.isVisible = true
+          wrapperBottom.add(component)
+          dummy.preferredSize = component.preferredSize
+          wrapperBody.add(dummy)
+        }
+      }
+    }
+  }
+}