Finish converting cursors to use markers.

The model layer works at least… haven't tested the view. Will test out
the view once I get the selection model working.

spec/app/buffer-spec.coffee

@@ -727,6 +727,30 @@ describe 'Buffer', ->
           buffer.setMarkerHeadPosition(marker, [6, 2])
           expect(observeHandler).not.toHaveBeenCalled()
 
+    describe "marker destruction", ->
+      marker = null
+
+      beforeEach ->
+        marker = buffer.markRange([[4, 20], [4, 23]])
+
+      it "allows a marker to be destroyed", ->
+        buffer.destroyMarker(marker)
+        expect(buffer.getMarkerRange(marker)).toBeUndefined()
+
+      it "does not restore invalidated markers that have been destroyed", ->
+        buffer.delete([[4, 15], [4, 25]])
+        expect(buffer.getMarkerRange(marker)).toBeUndefined()
+        buffer.destroyMarker(marker)
+        buffer.undo()
+        expect(buffer.getMarkerRange(marker)).toBeUndefined()
+
+        # even "stayValid" markers get destroyed properly
+        marker2 = buffer.markRange([[4, 20], [4, 23]], stayValid: true)
+        buffer.delete([[4, 15], [4, 25]])
+        buffer.destroyMarker(marker2)
+        buffer.undo()
+        expect(buffer.getMarkerRange(marker2)).toBeUndefined()
+
     describe "marker updates due to buffer changes", ->
       [marker1, marker2] = []
 

spec/app/display-buffer-spec.coffee

@@ -584,7 +584,7 @@ describe "DisplayBuffer", ->
     beforeEach ->
       displayBuffer.foldBufferRow(4)
 
-    describe "creation and manipulation", ->
+    describe "marker creation and manipulation", ->
       it "allows markers to be created in terms of both screen and buffer coordinates", ->
         marker1 = displayBuffer.markScreenRange([[5, 4], [5, 10]])
         marker2 = displayBuffer.markBufferRange([[8, 4], [8, 10]])
@@ -603,7 +603,15 @@ describe "DisplayBuffer", ->
         expect(displayBuffer.isMarkerReversed(marker)).toBeTruthy()
         expect(displayBuffer.getMarkerBufferRange(marker)).toEqual [[5, 4], [8, 4]]
 
-    describe "observation", ->
+      it "clips screen positions before assigning them", ->
+        marker = displayBuffer.markScreenRange([[5, 4], [5, 10]])
+        displayBuffer.setMarkerHeadScreenPosition(marker, [-5, -4])
+        expect(displayBuffer.getMarkerBufferRange(marker)).toEqual [[0, 0], [8, 4]]
+
+        displayBuffer.setMarkerTailScreenPosition(marker, [-5, -4])
+        expect(displayBuffer.getMarkerBufferRange(marker)).toEqual [[0, 0], [0, 0]]
+
+    describe "marker observation", ->
       observeHandler = null
 
       beforeEach ->
@@ -662,3 +670,12 @@ describe "DisplayBuffer", ->
 
           displayBuffer.unfoldBufferRow(4)
           expect(observeHandler).not.toHaveBeenCalled()
+
+    describe "marker destruction", ->
+      it "allows markers to be destroyed", ->
+        marker = displayBuffer.markScreenRange([[5, 4], [5, 10]])
+        displayBuffer.destroyMarker(marker)
+        expect(displayBuffer.getMarkerBufferRange(marker)).toBeUndefined()
+
+
+

spec/app/edit-session-spec.coffee

@@ -76,12 +76,12 @@ describe "EditSession", ->
 
       describe "when the cursor is on the first line", ->
         it "moves the cursor to the beginning of the line, but retains the goal column", ->
-          editSession.setCursorScreenPosition(row: 0, column: 4)
+          editSession.setCursorScreenPosition([0, 4])
           editSession.moveCursorUp()
-          expect(editSession.getCursorScreenPosition()).toEqual(row: 0, column: 0)
+          expect(editSession.getCursorScreenPosition()).toEqual([0, 0])
 
           editSession.moveCursorDown()
-          expect(editSession.getCursorScreenPosition()).toEqual(row: 1, column: 4)
+          expect(editSession.getCursorScreenPosition()).toEqual([1, 4])
 
       it "merges cursors when they overlap", ->
         editSession.addCursorAtScreenPosition([1, 0])
@@ -185,9 +185,9 @@ describe "EditSession", ->
       describe "when the cursor is on the last column of a line", ->
         describe "when there is a subsequent line", ->
           it "wraps to the beginning of the next line", ->
-            editSession.setCursorScreenPosition(row: 0, column: buffer.lineForRow(0).length)
+            editSession.setCursorScreenPosition([0, buffer.lineForRow(0).length])
             editSession.moveCursorRight()
-            expect(editSession.getCursorScreenPosition()).toEqual(row: 1, column: 0)
+            expect(editSession.getCursorScreenPosition()).toEqual [1, 0]
 
         describe "when the cursor is on the last line", ->
           it "remains in the same position", ->