Show preview list when X x operation completes

spec/extensions/command-interpreter-spec.coffee

@@ -204,20 +204,21 @@ describe "CommandInterpreter", ->
           expect(cursors[1].getBufferPosition()).toEqual [6, 65]
           expect(cursors[2].getBufferPosition()).toEqual [7, 5]
 
-    it "loops through current selections and selects text matching the regex", ->
-      waitsForPromise ->
-        editSession.setSelectedBufferRange [[3,0], [3,62]]
-        editSession.addSelectionForBufferRange [[6,0], [6,65]]
-        interpreter.eval('x/current', editSession)
+    describe "when text is initially selected", ->
+      it "loops through current selections and selects text matching the regex", ->
+        waitsForPromise ->
+          editSession.setSelectedBufferRange [[3,0], [3,62]]
+          editSession.addSelectionForBufferRange [[6,0], [6,65]]
+          interpreter.eval('x/current', editSession)
 
-      runs ->
-        selections = editSession.getSelections()
-        expect(selections.length).toBe 4
+        runs ->
+          selections = editSession.getSelections()
+          expect(selections.length).toBe 4
 
-        expect(selections[0].getBufferRange()).toEqual [[3,31], [3,38]]
-        expect(selections[1].getBufferRange()).toEqual [[6,6], [6,13]]
-        expect(selections[2].getBufferRange()).toEqual [[6,34], [6,41]]
-        expect(selections[3].getBufferRange()).toEqual [[6,56], [6,63]]
+          expect(selections[0].getBufferRange()).toEqual [[3,31], [3,38]]
+          expect(selections[1].getBufferRange()).toEqual [[6,6], [6,13]]
+          expect(selections[2].getBufferRange()).toEqual [[6,34], [6,41]]
+          expect(selections[3].getBufferRange()).toEqual [[6,56], [6,63]]
 
   describe "substitution", ->
     it "does nothing if there are no matches", ->

spec/extensions/command-panel-spec.coffee

@@ -13,7 +13,7 @@ describe "CommandPanel", ->
     commandPanel = requireExtension('command-panel')
 
   afterEach ->
-    rootView.remove()
+    rootView.deactivate()
 
   describe "serialization", ->
     it "preserves the command panel's mini editor text and visibility across reloads", ->
@@ -119,6 +119,21 @@ describe "CommandPanel", ->
         expect(buffer.lineForRow(0)).toMatch /quicktorta/
         expect(buffer.lineForRow(1)).toMatch /var torta/
 
+    describe "when the command returns operations to be previewed", ->
+      fit "displays a preview of the operations above the mini-editor", ->
+        rootView.attachToDom()
+        editor.remove()
+
+        rootView.trigger 'command-panel:toggle'
+
+        commandPanel.miniEditor.insertText
+
+        waitsForPromise -> commandPanel.execute('X x/a+/')
+
+        runs ->
+          expect(commandPanel).toBeVisible()
+          expect(commandPanel.previewList).toBeVisible()
+
     describe "if the command is malformed", ->
       it "adds and removes an error class to the command panel and does not close it", ->
         rootView.trigger 'command-panel:toggle'

src/extensions/command-panel/command-panel.coffee

@@ -2,6 +2,7 @@
 CommandInterpreter = require 'command-panel/command-interpreter'
 RegexAddress = require 'command-panel/commands/regex-address'
 CompositeCommand = require 'command-panel/commands/composite-command'
+PreviewItem = require 'command-panel/preview-item'
 Editor = require 'editor'
 {SyntaxError} = require('pegjs').parser
 
@@ -16,6 +17,9 @@ class CommandPanel extends View
     else
       @instance = new CommandPanel(rootView)
 
+  @deactivate: ->
+    @instance.detach()
+
   @serialize: ->
     text: @instance.miniEditor.getText()
     visible: @instance.hasParent()
@@ -27,8 +31,10 @@ class CommandPanel extends View
 
   @content: ->
     @div class: 'command-panel', =>
-      @div ':', class: 'prompt', outlet: 'prompt'
-      @subview 'miniEditor', new Editor(mini: true)
+      @ol class: 'preview-list', outlet: 'previewList'
+      @div class: 'prompt-and-editor', =>
+        @div ':', class: 'prompt', outlet: 'prompt'
+        @subview 'miniEditor', new Editor(mini: true)
 
   commandInterpreter: null
   history: null
@@ -54,16 +60,25 @@ class CommandPanel extends View
 
   attach: (text='') ->
     @rootView.append(this)
+    @previewList.hide()
     @miniEditor.focus()
     @miniEditor.setText(text)
 
   detach: ->
     @rootView.focus()
+    if @previewedOperations
+      operation.destroy() for operation in @previewedOperations
     super
 
   execute: (command = @miniEditor.getText()) ->
     try
-      @commandInterpreter.eval(command, @rootView.getActiveEditSession())
+      @commandInterpreter.eval(command, @rootView.getActiveEditSession()).done (operations) =>
+        @history.push(command)
+        @historyIndex = @history.length
+        if operations?.length
+          @populatePreviewList(operations)
+        else
+          @detach()
     catch error
       if error instanceof SyntaxError
         @flashError()
@@ -71,9 +86,12 @@ class CommandPanel extends View
       else
         throw error
 
-    @history.push(command)
-    @historyIndex = @history.length
-    @detach()
+  populatePreviewList: (operations) ->
+    @previewedOperations = operations
+    @previewList.empty()
+    for operation in operations
+      @previewList.append(new PreviewItem(operation))
+    @previewList.show()
 
   navigateBackwardInHistory: ->
     return if @historyIndex == 0

src/extensions/command-panel/commands/composite-command.coffee

@@ -21,10 +21,10 @@ class CompositeCommand
         @executeCommands(remainingCommands, project, editSession, nextRanges).done ->
           deferred.resolve()
       else
-        editSession?.clearAllSelections() unless currentCommand.preserveSelections
         if currentCommand.previewOperations
           deferred.resolve(operations)
         else
+          editSession?.clearAllSelections() unless currentCommand.preserveSelections
           for operation in operations
             operation.execute(editSession)
             operation.destroy()

src/extensions/command-panel/operation.coffee

@@ -14,6 +14,9 @@ class Operation
     @buffer.change(@getBufferRange(), @newText) if @newText
     editSession.addSelectionForBufferRange(@getBufferRange()) unless @preserveSelection
 
+  preview: ->
+    "sad :-("
+
   destroy: ->
     @buffer.release()
     @anchorRange.destroy()

src/extensions/command-panel/preview-item.coffee

@@ -0,0 +1,8 @@
+{View} = require 'space-pen'
+
+module.exports =
+class PreviewItem extends View
+  @content: (operation) ->
+    @li =>
+      @span operation.getPath()
+      @span operation.preview()

static/command-panel.css

@@ -4,6 +4,14 @@
   width: 100%;
   background: #515151;
   padding: 3px;
+}
+
+.command-panel .preview-list {
+  max-height: 300px;
+  overflow: auto;
+}
+
+.command-panel .prompt-and-editor {
   display: -webkit-box;
 }