Store hidden input data in TextEditorPresenter::state

spec/text-editor-presenter-spec.coffee

@@ -323,6 +323,69 @@ describe "TextEditorPresenter", ->
           expectStateUpdate presenter, -> atom.config.set("editor.scrollPastEnd", false)
           expect(presenter.state.verticalScrollbar.scrollTop).toBe presenter.contentHeight - presenter.clientHeight
 
+    describe ".hiddenInput", ->
+      describe ".top/.left", ->
+        it "is positioned over the last cursor it is in view and the editor is focused", ->
+          editor.setCursorBufferPosition([3, 6])
+          presenter = buildPresenter(focused: false, explicitHeight: 50, contentFrameWidth: 300, horizontalScrollbarHeight: 0, verticalScrollbarWidth: 0)
+          expectValues presenter.state.hiddenInput, {top: 0, left: 0}
+
+          expectStateUpdate presenter, -> presenter.setFocused(true)
+          expectValues presenter.state.hiddenInput, {top: 3 * 10, left: 6 * 10}
+
+          expectStateUpdate presenter, -> presenter.setScrollTop(15)
+          expectValues presenter.state.hiddenInput, {top: (3 * 10) - 15, left: 6 * 10}
+
+          expectStateUpdate presenter, -> presenter.setScrollLeft(35)
+          expectValues presenter.state.hiddenInput, {top: (3 * 10) - 15, left: (6 * 10) - 35}
+
+          expectStateUpdate presenter, -> presenter.setScrollTop(40)
+          expectValues presenter.state.hiddenInput, {top: 0, left: (6 * 10) - 35}
+
+          expectStateUpdate presenter, -> presenter.setScrollLeft(70)
+          expectValues presenter.state.hiddenInput, {top: 0, left: 0}
+
+          expectStateUpdate presenter, -> editor.setCursorBufferPosition([11, 43])
+          expectValues presenter.state.hiddenInput, {top: 50 - 10, left: 300 - 10}
+
+          newCursor = null
+          expectStateUpdate presenter, -> newCursor = editor.addCursorAtBufferPosition([6, 10])
+          expectValues presenter.state.hiddenInput, {top: (6 * 10) - 40, left: (10 * 10) - 70}
+
+          expectStateUpdate presenter, -> newCursor.destroy()
+          expectValues presenter.state.hiddenInput, {top: 50 - 10, left: 300 - 10}
+
+          expectStateUpdate presenter, -> presenter.setFocused(false)
+          expectValues presenter.state.hiddenInput, {top: 0, left: 0}
+
+      describe ".height", ->
+        it "is assigned based on the line height", ->
+          presenter = buildPresenter()
+          expect(presenter.state.hiddenInput.height).toBe 10
+
+          expectStateUpdate presenter, -> presenter.setLineHeight(20)
+          expect(presenter.state.hiddenInput.height).toBe 20
+
+      describe ".width", ->
+        it "is assigned based on the width of the character following the cursor", ->
+          waitsForPromise -> atom.packages.activatePackage('language-javascript')
+
+          runs ->
+            editor.setCursorBufferPosition([3, 6])
+            presenter = buildPresenter()
+            expect(presenter.state.hiddenInput.width).toBe 10
+
+            expectStateUpdate presenter, -> presenter.setBaseCharacterWidth(15)
+            expect(presenter.state.hiddenInput.width).toBe 15
+
+            expectStateUpdate presenter, -> presenter.setScopedCharacterWidth(['source.js', 'storage.modifier.js'], 'r', 20)
+            expect(presenter.state.hiddenInput.width).toBe 20
+
+        it "is 2px at the end of lines", ->
+          presenter = buildPresenter()
+          editor.setCursorBufferPosition([3, Infinity])
+          expect(presenter.state.hiddenInput.width).toBe 2
+
     describe ".content", ->
       describe ".scrollingVertically", ->
         it "is true for ::stoppedScrollingDelay milliseconds following a changes to ::scrollTop", ->

src/text-editor-presenter.coffee

@@ -86,6 +86,7 @@ class TextEditorPresenter
     @state =
       horizontalScrollbar: {}
       verticalScrollbar: {}
+      hiddenInput: {}
       content:
         scrollingVertically: false
         blinkCursorsOff: false
@@ -106,6 +107,7 @@ class TextEditorPresenter
     @updateVerticalScrollState()
     @updateHorizontalScrollState()
     @updateScrollbarsState()
+    @updateHiddenInputState()
     @updateContentState()
     @updateDecorations()
     @updateLinesState()
@@ -153,6 +155,25 @@ class TextEditorPresenter
 
     @emitter.emit 'did-update-state'
 
+  updateHiddenInputState: ->
+    return unless lastCursor = @model.getLastCursor()
+
+    {top, left, height, width} = @pixelRectForScreenRange(lastCursor.getScreenRange())
+
+    if @focused
+      top -= @scrollTop
+      left -= @scrollLeft
+      @state.hiddenInput.top = Math.max(Math.min(top, @clientHeight - height), 0)
+      @state.hiddenInput.left = Math.max(Math.min(left, @clientWidth - width), 0)
+    else
+      @state.hiddenInput.top = 0
+      @state.hiddenInput.left = 0
+
+    @state.hiddenInput.height = height
+    @state.hiddenInput.width = Math.max(width, 2)
+
+    @emitter.emit 'did-update-state'
+
   updateContentState: ->
     @state.content.scrollWidth = @scrollWidth
     @state.content.scrollLeft = @scrollLeft
@@ -448,6 +469,11 @@ class TextEditorPresenter
 
   getCursorBlinkResumeDelay: -> @cursorBlinkResumeDelay
 
+  setFocused: (focused) ->
+    unless @focused is focused
+      @focused = focused
+      @updateHiddenInputState()
+
   setScrollTop: (scrollTop) ->
     scrollTop = @constrainScrollTop(scrollTop)
 
@@ -458,6 +484,7 @@ class TextEditorPresenter
       @updateEndRow()
       @didStartScrolling()
       @updateVerticalScrollState()
+      @updateHiddenInputState()
       @updateDecorations()
       @updateLinesState()
       @updateCursorsState()
@@ -487,6 +514,7 @@ class TextEditorPresenter
       @scrollLeft = scrollLeft
       @model.setScrollLeft(scrollLeft)
       @updateHorizontalScrollState()
+      @updateHiddenInputState()
       @updateCursorsState() unless oldScrollLeft?
 
   setHorizontalScrollbarHeight: (horizontalScrollbarHeight) ->
@@ -576,6 +604,7 @@ class TextEditorPresenter
       @updateHorizontalScrollState()
       @updateVerticalScrollState()
       @updateScrollbarsState()
+      @updateHiddenInputState()
       @updateDecorations()
       @updateLinesState()
       @updateCursorsState()
@@ -623,6 +652,7 @@ class TextEditorPresenter
     @updateHorizontalScrollState()
     @updateVerticalScrollState()
     @updateScrollbarsState()
+    @updateHiddenInputState()
     @updateContentState()
     @updateDecorations()
     @updateLinesState()
@@ -886,6 +916,7 @@ class TextEditorPresenter
 
   observeCursor: (cursor) ->
     didChangePositionDisposable = cursor.onDidChangePosition =>
+      @updateHiddenInputState() if cursor.isLastCursor()
       @pauseCursorBlinking()
       @updateCursorsState()
 
@@ -895,6 +926,7 @@ class TextEditorPresenter
       @disposables.remove(didChangePositionDisposable)
       @disposables.remove(didChangeVisibilityDisposable)
       @disposables.remove(didDestroyDisposable)
+      @updateHiddenInputState()
       @updateCursorsState()
 
     @disposables.add(didChangePositionDisposable)
@@ -903,6 +935,7 @@ class TextEditorPresenter
 
   didAddCursor: (cursor) ->
     @observeCursor(cursor)
+    @updateHiddenInputState()
     @pauseCursorBlinking()
     @updateCursorsState()