not treat non-visible edge cells as visible (#31)

* make cells that is on the edge not visible * add test
SoySauceLab · Oct 16, 2017 · 15843a1 · 15843a1
1 parent 1e1b5fb
commit 15843a1
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Showing 2 changed files with 11 additions and 4 deletions.
diff --git a/CollectionKitTests/FlowLayoutSpec.swift b/CollectionKitTests/FlowLayoutSpec.swift
@@ -45,6 +45,13 @@ class FlowLayoutSpec: QuickSpec {
         layout.mockLayout(parentSize: (130, 130), (50, 50), (50, 50), (50, 50))
         expect(layout.frames).to(equal(frames((0, 0, 50, 50), (60, 0, 50, 50), (0, 60, 50, 50))))
       }
+
+      it("should not display cells outside of the visible area") {
+        let layout = FlowLayout<CGSize>().transposed()
+        layout.mockLayout(parentSize: (100, 50), (50, 50), (50, 50), (50, 50), (50, 50))
+        let visible = layout.visibleIndexes(activeFrame: CGRect(x: 50, y: 0, width: 100, height: 50))
+        expect(visible).to(equal([1, 2]))
+      }
     }
   }
 }

diff --git a/Sources/Layout/SimpleLayout.swift b/Sources/Layout/SimpleLayout.swift
@@ -64,10 +64,10 @@ open class VerticalSimpleLayout<Data>: SimpleLayout<Data> {
     var visibleIndexes = [Int]()
     while index < frames.count {
       let frame = frames[index]
-      if frame.minY > activeFrame.maxY {
+      if frame.minY >= activeFrame.maxY {
         break
       }
-      if frame.maxY >= activeFrame.minY {
+      if frame.maxY > activeFrame.minY {
         visibleIndexes.append(index)
       }
       index += 1
@@ -88,10 +88,10 @@ open class HorizontalSimpleLayout<Data>: SimpleLayout<Data> {
     var visibleIndexes = [Int]()
     while index < frames.count {
       let frame = frames[index]
-      if frame.minX > activeFrame.maxX {
+      if frame.minX >= activeFrame.maxX {
         break
       }
-      if frame.maxX >= activeFrame.minX {
+      if frame.maxX > activeFrame.minX {
         visibleIndexes.append(index)
       }
       index += 1