Move the cursor on single click

spec/editor-component-spec.coffee

@@ -162,6 +162,22 @@ describe "EditorComponent", ->
       expect(region3Rect.left).toBe 0
       expect(region3Rect.width).toBe 10 * charWidth
 
+  describe "mouse interactions", ->
+    clientCoordinatesForScreenPosition = (screenPosition) ->
+      positionOffset = editor.pixelPositionForScreenPosition(screenPosition)
+      editorClientRect = node.getBoundingClientRect()
+      clientX = editorClientRect.left + positionOffset.left
+      clientY = editorClientRect.top + positionOffset.top - editor.getScrollTop()
+      {clientX, clientY}
+
+    describe "when a non-folded line is single-clicked", ->
+      it "moves the cursor to the nearest row and column", ->
+        node.style.height = 4.5 * lineHeightInPixels + 'px'
+        component.updateAllDimensions()
+        editor.setScrollTop(3.5 * lineHeightInPixels)
+        component.onMouseDown(clientCoordinatesForScreenPosition([4, 8]))
+        expect(editor.getCursorScreenPosition()).toEqual [4, 8]
+
   it "transfers focus to the hidden input", ->
     expect(document.activeElement).toBe document.body
     node.focus()

src/display-buffer.coffee

@@ -383,6 +383,25 @@ class DisplayBuffer extends Model
         column++
     {top, left}
 
+  screenPositionForPixelPosition: (pixelPosition) ->
+    targetTop = pixelPosition.top
+    targetLeft = pixelPosition.left
+    row = Math.floor(targetTop / @getLineHeight())
+    row = Math.min(row, @getLastRow())
+    row = Math.max(0, row)
+
+    left = 0
+    column = 0
+    for token in @lineForRow(row).tokens
+      charWidths = @getScopedCharWidths(token.scopes)
+      for char in token.value
+        charWidth = charWidths[char] ? defaultCharWidth
+        break if targetLeft <= left + (charWidth / 2)
+        left += charWidth
+        column++
+
+    new Point(row, column)
+
   # Gets the number of screen lines.
   #
   # Returns a {Number}.

src/editor-component.coffee

@@ -38,7 +38,7 @@ EditorCompont = React.createClass
     height = editor.getScrollHeight()
     WebkitTransform = "translateY(#{-editor.getScrollTop()}px)"
 
-    div className: 'scrollable-content', style: {height, WebkitTransform},
+    div className: 'scrollable-content', style: {height, WebkitTransform}, onMouseDown: @onMouseDown,
       @renderCursors()
       @renderVisibleLines()
       @renderUnderlayer()
@@ -267,6 +267,17 @@ EditorCompont = React.createClass
     @refs.verticalScrollbar.getDOMNode().scrollTop -= event.wheelDeltaY
     event.preventDefault()
 
+  onMouseDown: (event) ->
+    {editor} = @props
+    {clientX, clientY} = event
+    editorClientRect = @refs.scrollView.getDOMNode().getBoundingClientRect()
+
+    pixelPosition =
+      top: clientY - editorClientRect.top + editor.getScrollTop()
+      left: clientX - editorClientRect.left
+    screenPosition = editor.screenPositionForPixelPosition(pixelPosition)
+    editor.setCursorScreenPosition(screenPosition)
+
   clearVisibleRowOverrides: ->
     @visibleRowOverrides = null
     @forceUpdate()

src/editor.coffee

@@ -153,7 +153,8 @@ class Editor extends Model
   @delegatesMethods 'setLineHeight', 'getLineHeight', 'setDefaultCharWidth', 'setHeight',
     'getHeight', 'setWidth', 'getWidth', 'setScrollTop', 'getScrollTop', 'getScrollBottom',
     'setScrollBottom', 'setScrollLeft', 'getScrollLeft', 'getScrollHeight', 'getVisibleRowRange',
-    'intersectsVisibleRowRange', 'selectionIntersectsVisibleRowRange', toProperty: 'displayBuffer'
+    'intersectsVisibleRowRange', 'selectionIntersectsVisibleRowRange', 'pixelPositionForScreenPosition',
+    'screenPositionForPixelPosition', toProperty: 'displayBuffer'
 
   @delegatesProperties '$lineHeight', '$defaultCharWidth', '$height', '$width',
     '$scrollTop', '$scrollLeft', toProperty: 'displayBuffer'
@@ -512,8 +513,6 @@ class Editor extends Model
   # this editor.
   shouldPromptToSave: -> @isModified() and not @buffer.hasMultipleEditors()
 
-  pixelPositionForScreenPosition: (screenPosition) -> @displayBuffer.pixelPositionForScreenPosition(screenPosition)
-
   # Public: Convert a position in buffer-coordinates to screen-coordinates.
   #
   # The position is clipped via {::clipBufferPosition} prior to the conversion.