Improve issue pagination.

src/main/scala/view/Pagination.scala

@@ -0,0 +1,50 @@
+package view
+
+/**
+ * Provides control information for pagination.
+ * This class is used by paginator.scala.html.
+ *
+ * @param page the current page number
+ * @param count the total record count
+ * @param limit the limit record count per one page
+ * @param width the width (number of cells) of the paginator
+ */
+case class Pagination(page: Int, count: Int, limit: Int, width: Int){
+
+  /**
+   * max page number
+   */
+  val max = (count - 1) / limit + 1
+
+  /**
+   * whether to omit the left side
+   */
+  val omitLeft  = width / 2 < page
+
+  /**
+   * whether to omit the right side
+   */
+  val omitRight = max - width / 2 > page
+
+  /**
+   * Returns true if given page number is visible.
+   */
+  def visibleFor(i: Int): Boolean = {
+    if(i == 1 || i == max){
+      true
+    } else {
+      val leftRange  = page - width / 2 + (if(omitLeft) 2 else 0)
+      val rightRange = page + width / 2 - (if(omitRight) 2 else 0)
+
+      val fixedRange = if(leftRange < 1){
+        (1, rightRange + (leftRange * -1) + 1)
+      } else if(rightRange > max){
+        (leftRange - (rightRange - max), max)
+      } else {
+        (leftRange, rightRange)
+      }
+
+      (i >= fixedRange._1 && i <= fixedRange._2)
+    }
+  }
+}