vcs: Implement initial non-modal commit layout

platform/platform-resources/src/idea/VcsActions.xml

@@ -293,6 +293,10 @@
 
     <group id="Vcs.CommitExecutor.Actions"/>
 
+    <group id="ChangesView.CommitToolbar">
+      <reference id="Vcs.MessageActionGroup"/>
+    </group>
+
     <action class="com.intellij.openapi.vcs.actions.VcsToolbarLabelAction" id="VcsToolbarLabelAction" text="VCS Label"/>
 
     <group id="VcsToobarActions">

platform/vcs-impl/src/com/intellij/openapi/vcs/changes/ChangesViewManager.java

@@ -179,8 +179,14 @@ public class ChangesViewManager implements ChangesViewI, ProjectComponent, Persi
     ActionToolbar changesToolbar = createChangesToolbar();
     addBorder(changesToolbar.getComponent(), createBorder(JBColor.border(), SideBorder.RIGHT));
     BorderLayoutPanel changesPanel = simplePanel(createScrollPane(myView)).addToLeft(changesToolbar.getComponent());
+
+    BorderLayoutPanel contentPanel = simplePanel(changesPanel);
+    if (isNonModalCommit()) {
+      contentPanel.addToBottom(new ChangesViewCommitPanel(myProject));
+    }
+
     MyChangeProcessor changeProcessor = new MyChangeProcessor(myProject);
-    mySplitterComponent = new PreviewDiffSplitterComponent(changesPanel, changeProcessor, CHANGES_VIEW_PREVIEW_SPLITTER_PROPORTION,
+    mySplitterComponent = new PreviewDiffSplitterComponent(contentPanel, changeProcessor, CHANGES_VIEW_PREVIEW_SPLITTER_PROPORTION,
                                                            myVcsConfiguration.LOCAL_CHANGES_DETAILS_PREVIEW_SHOWN);
 
     myView.installPopupHandler((DefaultActionGroup)ActionManager.getInstance().getAction("ChangesViewPopupMenu"));

platform/vcs-impl/src/com/intellij/openapi/vcs/changes/ui/ChangesViewCommitPanel.kt

+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.intellij.openapi.vcs.changes.ui
+
+import com.intellij.openapi.actionSystem.ActionGroup
+import com.intellij.openapi.actionSystem.ActionManager
+import com.intellij.openapi.actionSystem.DataProvider
+import com.intellij.openapi.project.Project
+import com.intellij.openapi.vcs.ui.CommitMessage
+import com.intellij.ui.IdeBorderFactory.createBorder
+import com.intellij.ui.JBColor
+import com.intellij.ui.SideBorder
+import com.intellij.util.ui.JBUI.Borders.emptyLeft
+import com.intellij.util.ui.JBUI.Panels.simplePanel
+import com.intellij.util.ui.UIUtil.addBorder
+import com.intellij.util.ui.UIUtil.getTreeBackground
+import com.intellij.util.ui.components.BorderLayoutPanel
+import javax.swing.JButton
+
+class ChangesViewCommitPanel(val project: Project) : BorderLayoutPanel(), DataProvider {
+  val actions = ActionManager.getInstance().getAction("ChangesView.CommitToolbar") as ActionGroup
+  val toolbar = ActionManager.getInstance().createActionToolbar("ChangesView.CommitToolbar", actions, false).apply {
+    setTargetComponent(this@ChangesViewCommitPanel)
+    addBorder(component, createBorder(JBColor.border(), SideBorder.RIGHT))
+  }
+  val commitMessage = CommitMessage(project, false, false, true).apply {
+    editorField.addSettingsProvider { it.setBorder(emptyLeft(3)) }
+    editorField.setPlaceholder("Commit Message")
+  }
+
+  init {
+    val commitButton = object : JButton("Commit") {
+      override fun isDefaultButton() = true
+    }
+    val buttonPanel = simplePanel()
+      .addToLeft(commitButton)
+      .withBackground(getTreeBackground())
+    val centerPanel = simplePanel(commitMessage).addToBottom(buttonPanel)
+
+    addToCenter(centerPanel).addToLeft(toolbar.component).withBorder(createBorder(JBColor.border(), SideBorder.TOP))
+    withPreferredHeight(85)
+  }
+
+  override fun getData(dataId: String) = commitMessage.getData(dataId)
+}
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