Pass view measurements to model via presenter

Someday, we won’t need to pass measurements to the model anymore.

spec/text-editor-presenter-spec.coffee

@@ -137,7 +137,7 @@ describe "TextEditorPresenter", ->
             expect(presenter.state.horizontalScrollbar.scrollWidth).toBe (10 * (maxLineLength - 2)) + (20 * 2) + 1 # 2 of the characters are 20px wide now instead of 10px wide
 
         it "updates when ::softWrapped changes on the editor", ->
-          presenter = buildPresenter(contentFrameWidth: 50, baseCharacterWidth: 10)
+          presenter = buildPresenter(contentFrameWidth: 470, baseCharacterWidth: 10)
           expect(presenter.state.horizontalScrollbar.scrollWidth).toBe 10 * editor.getMaxScreenLineLength() + 1
           expectStateUpdate presenter, -> editor.setSoftWrapped(true)
           expect(presenter.state.horizontalScrollbar.scrollWidth).toBe 10 * editor.getMaxScreenLineLength()
@@ -180,6 +180,11 @@ describe "TextEditorPresenter", ->
           expectStateUpdate presenter, -> editor.getBuffer().insert([6, 0], new Array(100).join('x'))
           expect(presenter.state.horizontalScrollbar.scrollLeft).toBe scrollLeftBefore
 
+        it "never goes negative", ->
+          presenter = buildPresenter(scrollLeft: 10, verticalScrollbarWidth: 10, contentFrameWidth: 500)
+          expectStateUpdate presenter, -> presenter.setScrollLeft(-300)
+          expect(presenter.state.horizontalScrollbar.scrollLeft).toBe 0
+
     describe ".verticalScrollbar", ->
       describe ".visible", ->
         it "is true if the scrollHeight exceeds the computed client height", ->
@@ -278,6 +283,11 @@ describe "TextEditorPresenter", ->
           expectStateUpdate presenter, -> editor.getBuffer().insert([9, Infinity], '\n\n\n')
           expect(presenter.state.verticalScrollbar.scrollTop).toBe scrollTopBefore
 
+        it "never goes negative", ->
+          presenter = buildPresenter(scrollTop: 10, height: 50, horizontalScrollbarHeight: 10)
+          expectStateUpdate presenter, -> presenter.setScrollTop(-100)
+          expect(presenter.state.verticalScrollbar.scrollTop).toBe 0
+
     describe ".content", ->
       describe ".scrollingVertically", ->
         it "is true for ::stoppedScrollingDelay milliseconds following a changes to ::scrollTop", ->
@@ -354,7 +364,7 @@ describe "TextEditorPresenter", ->
             expect(presenter.state.content.scrollWidth).toBe (10 * (maxLineLength - 2)) + (20 * 2) + 1 # 2 of the characters are 20px wide now instead of 10px wide
 
         it "updates when ::softWrapped changes on the editor", ->
-          presenter = buildPresenter(contentFrameWidth: 50, baseCharacterWidth: 10)
+          presenter = buildPresenter(contentFrameWidth: 470, baseCharacterWidth: 10)
           expect(presenter.state.content.scrollWidth).toBe 10 * editor.getMaxScreenLineLength() + 1
           expectStateUpdate presenter, -> editor.setSoftWrapped(true)
           expect(presenter.state.content.scrollWidth).toBe 10 * editor.getMaxScreenLineLength()
@@ -397,6 +407,12 @@ describe "TextEditorPresenter", ->
           expectStateUpdate presenter, -> editor.getBuffer().insert([9, Infinity], '\n\n\n')
           expect(presenter.state.content.scrollTop).toBe scrollTopBefore
 
+        it "never goes negative", ->
+          presenter = buildPresenter(scrollTop: 10, height: 50, horizontalScrollbarHeight: 10)
+          expectStateUpdate presenter, -> presenter.setScrollTop(-100)
+          expect(presenter.state.content.scrollTop).toBe 0
+
+      describe ".scrollLeft", ->
         it "tracks the value of ::scrollLeft", ->
           presenter = buildPresenter(scrollLeft: 10, lineHeight: 10, baseCharacterWidth: 10, verticalScrollbarWidth: 10, contentFrameWidth: 500)
           expect(presenter.state.content.scrollLeft).toBe 10
@@ -422,6 +438,11 @@ describe "TextEditorPresenter", ->
           expectStateUpdate presenter, -> editor.getBuffer().insert([6, 0], new Array(100).join('x'))
           expect(presenter.state.content.scrollLeft).toBe scrollLeftBefore
 
+        it "never goes negative", ->
+          presenter = buildPresenter(scrollLeft: 10, verticalScrollbarWidth: 10, contentFrameWidth: 500)
+          expectStateUpdate presenter, -> presenter.setScrollLeft(-300)
+          expect(presenter.state.content.scrollLeft).toBe 0
+
       describe ".indentGuidesVisible", ->
         it "is initialized based on the editor.showIndentGuide config setting", ->
           presenter = buildPresenter()
@@ -1477,6 +1498,11 @@ describe "TextEditorPresenter", ->
           expectStateUpdate presenter, -> editor.getBuffer().insert([9, Infinity], '\n\n\n')
           expect(presenter.state.gutter.scrollTop).toBe scrollTopBefore
 
+        it "never goes negative", ->
+          presenter = buildPresenter(scrollTop: 10, height: 50, horizontalScrollbarHeight: 10)
+          expectStateUpdate presenter, -> presenter.setScrollTop(-100)
+          expect(presenter.state.gutter.scrollTop).toBe 0
+
       describe ".backgroundColor", ->
         it "is assigned to ::gutterBackgroundColor if present, and to ::backgroundColor otherwise", ->
           presenter = buildPresenter(backgroundColor: "rgba(255, 0, 0, 0)", gutterBackgroundColor: "rgba(0, 255, 0, 0)")

src/text-editor-component.coffee

@@ -230,8 +230,6 @@ TextEditorComponent = React.createClass
     @subscribe editor.observeGrammar(@onGrammarChanged)
     @subscribe editor.observeCursors(@onCursorAdded)
     @subscribe editor.observeSelections(@onSelectionAdded)
-    @subscribe editor.$scrollTop.changes, @onScrollTopChanged
-    @subscribe editor.$scrollLeft.changes, @onScrollLeftChanged
     @subscribe editor.$verticalScrollbarWidth.changes, @requestUpdate
     @subscribe editor.$horizontalScrollbarHeight.changes, @requestUpdate
     @subscribe editor.$height.changes, @requestUpdate
@@ -356,7 +354,6 @@ TextEditorComponent = React.createClass
         pendingScrollTop = @pendingScrollTop
         @pendingScrollTop = null
         @presenter.setScrollTop(pendingScrollTop)
-        @props.editor.setScrollTop(pendingScrollTop)
 
   onHorizontalScroll: (scrollLeft) ->
     {editor} = @props
@@ -367,7 +364,6 @@ TextEditorComponent = React.createClass
     @pendingScrollLeft = scrollLeft
     unless animationFramePending
       @requestAnimationFrame =>
-        @props.editor.setScrollLeft(@pendingScrollLeft)
         @presenter.setScrollLeft(@pendingScrollLeft)
         @pendingScrollLeft = null
 
@@ -389,13 +385,13 @@ TextEditorComponent = React.createClass
     if Math.abs(wheelDeltaX) > Math.abs(wheelDeltaY)
       # Scrolling horizontally
       previousScrollLeft = editor.getScrollLeft()
-      editor.setScrollLeft(previousScrollLeft - Math.round(wheelDeltaX * @scrollSensitivity))
+      @presenter.setScrollLeft(previousScrollLeft - Math.round(wheelDeltaX * @scrollSensitivity))
       event.preventDefault() unless previousScrollLeft is editor.getScrollLeft()
     else
       # Scrolling vertically
       @presenter.setMouseWheelScreenRow(@screenRowForNode(event.target))
-      previousScrollTop = editor.getScrollTop()
-      editor.setScrollTop(previousScrollTop - Math.round(wheelDeltaY * @scrollSensitivity))
+      previousScrollTop = @presenter.scrollTop
+      @presenter.setScrollTop(previousScrollTop - Math.round(wheelDeltaY * @scrollSensitivity))
       event.preventDefault() unless previousScrollTop is editor.getScrollTop()
 
   onScrollViewScroll: ->
@@ -550,24 +546,6 @@ TextEditorComponent = React.createClass
       @selectionChanged = true
       @requestUpdate()
 
-  onScrollTopChanged: ->
-    @presenter.setScrollTop(@props.editor.getScrollTop())
-    @requestUpdate()
-    @onStoppedScrollingAfterDelay ?= debounce(@onStoppedScrolling, 200)
-    @onStoppedScrollingAfterDelay()
-
-  onScrollLeftChanged: ->
-    @presenter.setScrollLeft(@props.editor.getScrollLeft())
-    @requestUpdate()
-
-  onStoppedScrolling: ->
-    return unless @isMounted()
-
-    @mouseWheelScreenRow = null
-    @requestUpdate()
-
-  onStoppedScrollingAfterDelay: null # created lazily
-
   onCursorAdded: (cursor) ->
     @subscribe cursor.onDidChangePosition @onCursorMoved
 
@@ -675,18 +653,15 @@ TextEditorComponent = React.createClass
       height =  hostElement.offsetHeight
       if height > 0
         @presenter.setHeight(height)
-        editor.setHeight(height)
     else
       @presenter.setAutoHeight(true)
       @presenter.setHeight(null)
-      editor.setHeight(null)
 
     clientWidth = scrollViewNode.clientWidth
     paddingLeft = parseInt(getComputedStyle(scrollViewNode).paddingLeft)
     clientWidth -= paddingLeft
     if clientWidth > 0
       @presenter.setContentFrameWidth(clientWidth)
-      editor.setWidth(clientWidth)
 
   sampleFontStyling: ->
     oldFontSize = @fontSize
@@ -737,9 +712,7 @@ TextEditorComponent = React.createClass
     width = (cornerNode.offsetWidth - cornerNode.clientWidth) or 15
     height = (cornerNode.offsetHeight - cornerNode.clientHeight) or 15
 
-    editor.setVerticalScrollbarWidth(width)
     @presenter.setVerticalScrollbarWidth(width)
-    editor.setHorizontalScrollbarHeight(height)
     @presenter.setHorizontalScrollbarHeight(height)
 
     cornerNode.style.display = originalDisplayValue

src/text-editor-presenter.coffee

@@ -18,6 +18,7 @@ class TextEditorPresenter
     @disposables = new CompositeDisposable
     @emitter = new Emitter
     @charWidthsByScope = {}
+    @transferMeasurementsToModel()
     @observeModel()
     @observeConfig()
     @buildState()
@@ -29,6 +30,16 @@ class TextEditorPresenter
   onDidUpdateState: (callback) ->
     @emitter.on 'did-update-state', callback
 
+  transferMeasurementsToModel: ->
+    @model.setHeight(@height) if @height?
+    @model.setWidth(@contentFrameWidth) if @contentFrameWidth?
+    @model.setLineHeightInPixels(@lineHeight) if @lineHeight?
+    @model.setDefaultCharWidth(@baseCharacterWidth) if @baseCharacterWidth?
+    @model.setScrollTop(@scrollTop) if @scrollTop?
+    @model.setScrollLeft(@scrollLeft) if @scrollLeft?
+    @model.setVerticalScrollbarWidth(@verticalScrollbarWidth) if @verticalScrollbarWidth?
+    @model.setHorizontalScrollbarHeight(@horizontalScrollbarHeight) if @horizontalScrollbarHeight?
+
   observeModel: ->
     @disposables.add @model.onDidChange =>
       @updateHeightState()
@@ -49,6 +60,8 @@ class TextEditorPresenter
       @updateLineNumbersState()
     @disposables.add @model.onDidAddDecoration(@didAddDecoration.bind(this))
     @disposables.add @model.onDidAddCursor(@didAddCursor.bind(this))
+    @disposables.add @model.onDidChangeScrollTop(@setScrollTop.bind(this))
+    @disposables.add @model.onDidChangeScrollLeft(@setScrollLeft.bind(this))
     @observeDecoration(decoration) for decoration in @model.getDecorations()
     @observeCursor(cursor) for cursor in @model.getCursors()
 
@@ -346,16 +359,22 @@ class TextEditorPresenter
     @contentFrameWidth - @computeVerticalScrollbarWidth()
 
   computeScrollTop: ->
+    @scrollTop = @constrainScrollTop(@scrollTop)
+
+  constrainScrollTop: (scrollTop) ->
     if @hasRequiredMeasurements()
-      @scrollTop = Math.min(@scrollTop, @computeScrollHeight() - @computeClientHeight())
+      Math.max(0, Math.min(scrollTop, @computeScrollHeight() - @computeClientHeight()))
     else
-      @scrollTop
+      Math.max(0, scrollTop) if scrollTop?
 
   computeScrollLeft: ->
+    @scrollLeft = @constrainScrollLeft(@scrollLeft)
+
+  constrainScrollLeft: (scrollLeft) ->
     if @hasRequiredMeasurements()
-      @scrollLeft = Math.min(@scrollLeft, @computeScrollWidth() - @computeClientWidth())
+      Math.max(0, Math.min(scrollLeft, @computeScrollWidth() - @computeClientWidth()))
     else
-      @scrollLeft
+      Math.max(0, scrollLeft) if scrollLeft?
 
   computeHorizontalScrollbarHeight: ->
     contentWidth = @computeContentWidth()
@@ -423,8 +442,10 @@ class TextEditorPresenter
       @horizontalScrollbarHeight?
 
   setScrollTop: (scrollTop) ->
+    scrollTop = @constrainScrollTop(scrollTop)
     unless @scrollTop is scrollTop
       @scrollTop = scrollTop
+      @model.setScrollTop(scrollTop)
       @didStartScrolling()
       @updateVerticalScrollState()
       @updateDecorations()
@@ -450,19 +471,23 @@ class TextEditorPresenter
       @emitter.emit 'did-update-state'
 
   setScrollLeft: (scrollLeft) ->
+    scrollLeft = @constrainScrollLeft(scrollLeft)
     unless @scrollLeft is scrollLeft
       @scrollLeft = scrollLeft
+      @model.setScrollLeft(scrollLeft)
       @updateHorizontalScrollState()
 
   setHorizontalScrollbarHeight: (horizontalScrollbarHeight) ->
     unless @horizontalScrollbarHeight is horizontalScrollbarHeight
       @horizontalScrollbarHeight = horizontalScrollbarHeight
+      @model.setHorizontalScrollbarHeight(horizontalScrollbarHeight)
       @updateScrollbarsState()
       @updateVerticalScrollState()
 
   setVerticalScrollbarWidth: (verticalScrollbarWidth) ->
     unless @verticalScrollbarWidth is verticalScrollbarWidth
       @verticalScrollbarWidth = verticalScrollbarWidth
+      @model.setVerticalScrollbarWidth(verticalScrollbarWidth)
       @updateScrollbarsState()
       @updateHorizontalScrollState()
 
@@ -474,6 +499,7 @@ class TextEditorPresenter
   setHeight: (height) ->
     unless @height is height
       @height = height
+      @model.setHeight(height)
       @updateVerticalScrollState()
       @updateScrollbarsState()
       @updateDecorations()
@@ -487,6 +513,7 @@ class TextEditorPresenter
   setContentFrameWidth: (contentFrameWidth) ->
     unless @contentFrameWidth is contentFrameWidth
       @contentFrameWidth = contentFrameWidth
+      @model.setWidth(contentFrameWidth)
       @updateVerticalScrollState()
       @updateHorizontalScrollState()
       @updateScrollbarsState()
@@ -523,6 +550,7 @@ class TextEditorPresenter
   setBaseCharacterWidth: (baseCharacterWidth) ->
     unless @baseCharacterWidth is baseCharacterWidth
       @baseCharacterWidth = baseCharacterWidth
+      @model.setDefaultCharWidth(baseCharacterWidth)
       @characterWidthsChanged()
 
   getScopedCharWidth: (scopeNames, char) ->