Add model method to compute the visible rows range

atom-minimap · Dec 12, 2014 · 5a38ef5 · 5a38ef5
1 parent 7aa71b9
commit 5a38ef5
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Showing 2 changed files with 14 additions and 2 deletions.
diff --git a/lib/minimap.coffee b/lib/minimap.coffee
@@ -21,8 +21,14 @@ class Minimap
 
   getLineHeight: -> @charHeight + @interline
 
+  getFirstVisibleRow: ->
+    Math.floor(@getMinimapScrollTop() / @getLineHeight())
+
+  getLastVisibleRow: ->
+    Math.ceil((@getMinimapScrollTop() + @textEditor.getHeight()) / @getLineHeight())
+
   getMinimapScrollTop: ->
-    @getTextEditorScrollRatio() * @getMinimapMaxScrollTop()
+    Math.abs(@getTextEditorScrollRatio() * @getMinimapMaxScrollTop())
 
   getMinimapMaxScrollTop: -> Math.max(0, @getHeight() - @textEditor.getHeight())
 

diff --git a/spec/minimap-spec.coffee b/spec/minimap-spec.coffee
@@ -42,9 +42,15 @@ describe 'Minimap', ->
     expect(minimap.getMinimapMaxScrollTop()).toEqual(largeLineCount * 5 - 50)
     expect(minimap.canScroll()).toBeTruthy()
 
+  it 'computes the first visible row in the minimap', ->
+    expect(minimap.getFirstVisibleRow()).toEqual(0)
+
+  it 'computes the last visible row in the minimap', ->
+    expect(minimap.getLastVisibleRow()).toEqual(10)
+
   describe 'when there is no scrolling needed to display the whole minimap', ->
     it 'returns 0 when computing the minimap scroll', ->
-      expect(minimap.getMinimapScrollTop()).toBeCloseTo(0)
+      expect(minimap.getMinimapScrollTop()).toEqual(0)
 
     it 'returns 0 when measuring the available minimap scroll', ->
       editor.setText(smallSample)