From 720f23745fcfe193948835ae4e41339925c3d62d Mon Sep 17 00:00:00 2001
From: lana-k <skochetova89@gmail.com>
Date: Wed, 17 Feb 2021 17:57:45 +0100
Subject: [PATCH] Splitpanes.vue refactoring

---
 src/components/Splitpanes.vue | 193 ++++++++++++----------------------
 src/splitter.js               |  54 ++++++++++
 2 files changed, 122 insertions(+), 125 deletions(-)
 create mode 100644 src/splitter.js

diff --git a/src/components/Splitpanes.vue b/src/components/Splitpanes.vue
index 5c08d15..42bcfa4 100644
--- a/src/components/Splitpanes.vue
+++ b/src/components/Splitpanes.vue
@@ -3,13 +3,13 @@
     ref="container"
     :class="[
       'splitpanes',
-      `splitpanes--${horizontal ? 'horizontal' : 'vertical'}`,
-      { 'splitpanes--dragging': touch.dragging }
+      `splitpanes-${horizontal ? 'horizontal' : 'vertical'}`,
+      { 'splitpanes-dragging': dragging }
     ]"
   >
     <div class="movable-splitter" ref="movableSplitter" :style="movableSplitterStyle" />
     <div
-      class="splitpanes__pane"
+      class="splitpanes-pane"
       ref="left"
       :size="paneBefore.size"
       max-size="30"
@@ -19,7 +19,7 @@
     </div>
     <!-- Splitter start-->
     <div
-      class="splitpanes__splitter"
+      class="splitpanes-splitter"
       @mousedown="onMouseDown"
       @touchstart="onMouseDown"
     >
@@ -32,7 +32,7 @@
         <div
           v-if="after.max === 100  && after.size > 0"
           class="toggle-btn"
-          @click="togglePane('before')"
+          @click="togglePane(paneBefore)"
         >
           <img
             class="direction-icon"
@@ -43,7 +43,7 @@
         <div
           v-if="before.max === 100 && before.size > 0"
           class="toggle-btn"
-          @click="togglePane('after')"
+          @click="togglePane(paneAfter)"
         >
           <img
             class="direction-icon"
@@ -55,7 +55,7 @@
     </div>
     <!-- splitter end -->
     <div
-      class="splitpanes__pane"
+      class="splitpanes-pane"
       ref="right"
       :style="styles.after"
     >
@@ -65,6 +65,7 @@
 </template>
 
 <script>
+import splitter from '@/splitter'
 
 export default {
   name: 'Splitpanes',
@@ -82,10 +83,7 @@ export default {
         before: this.before.size,
         after: this.after.size
       },
-      touch: {
-        mouseDown: false,
-        dragging: false
-      },
+      dragging: false,
       movableSplitter: {
         top: 0,
         left: 0,
@@ -108,72 +106,50 @@ export default {
     },
     directionBeforeIconStyle () {
       const expanded = this.paneBefore.size !== 0
-      const translation = 'translate(-50%, -50%)'
+      const translation = 'translate(-50%, -50%) '
+      let rotation = ''
+
       if (this.horizontal) {
-        return {
-          transform: `${translation} ${expanded ? 'rotate(90deg)' : 'rotate(-90deg)'}`
-        }
+        rotation = expanded ? 'rotate(90deg)' : 'rotate(-90deg)'
       } else {
-        return {
-          transform: `${translation} ${expanded ? 'rotate(0deg)' : 'rotate(180deg)'}`
-        }
+        rotation = expanded ? 'rotate(0deg)' : 'rotate(180deg)'
+      }
+
+      return {
+        transform: translation + rotation
       }
     },
     directionAfterIconStyle () {
       const expanded = this.paneAfter.size !== 0
       const translation = 'translate(-50%, -50%)'
+      let rotation = ''
+
       if (this.horizontal) {
-        return {
-          transform: `${translation} ${expanded ? 'rotate(-90deg)' : 'rotate(90deg)'}`
-        }
+        rotation = expanded ? 'rotate(-90deg)' : 'rotate(90deg)'
       } else {
-        return {
-          transform: `${translation} ${expanded ? 'rotate(180deg)' : 'rotate(0deg)'}`
-        }
+        rotation = expanded ? 'rotate(180deg)' : 'rotate(0deg)'
+      }
+
+      return {
+        transform: translation + rotation
       }
     }
   },
 
   methods: {
-    bindEvents () {
-      document.addEventListener('mousemove', this.onMouseMove, { passive: false })
-      document.addEventListener('mouseup', this.onMouseUp)
-
-      // Passive: false to prevent scrolling while touch dragging.
-      if ('ontouchstart' in window) {
-        document.addEventListener('touchmove', this.onMouseMove, { passive: false })
-        document.addEventListener('touchend', this.onMouseUp)
-      }
-    },
-
-    unbindEvents () {
-      document.removeEventListener('mousemove', this.onMouseMove, { passive: false })
-      document.removeEventListener('mouseup', this.onMouseUp)
-
-      if ('ontouchstart' in window) {
-        document.removeEventListener('touchmove', this.onMouseMove, { passive: false })
-        document.removeEventListener('touchend', this.onMouseUp)
-      }
-    },
-
     onMouseDown () {
-      this.bindEvents()
-      this.touch.mouseDown = true
+      splitter.bindEvents(this.onMouseMove, this.onMouseUp)
     },
 
     onMouseMove (event) {
-      if (this.touch.mouseDown) {
-        // Prevent scrolling while touch dragging (only works with an active event, eg. passive: false).
-        event.preventDefault()
-        this.touch.dragging = true
-        this.$set(this.movableSplitter, 'visibility', 'visible')
-        this.moveSplitter(event)
-      }
+      event.preventDefault()
+      this.dragging = true
+      this.$set(this.movableSplitter, 'visibility', 'visible')
+      this.moveSplitter(event)
     },
 
     onMouseUp () {
-      this.touch.mouseDown = false
-      if (this.touch.dragging) {
+      if (this.dragging) {
         const dragPercentage = this.horizontal
           ? this.movableSplitter.top
           : this.movableSplitter.left
@@ -186,65 +162,32 @@ export default {
           left: 0,
           visibility: 'hidden'
         }
+
+        this.dragging = false
       }
 
-      // Keep dragging flag until click event is finished (click happens immediately after mouseup)
-      // in order to prevent emitting `splitter-click` event if splitter was dragged.
-      setTimeout(() => {
-        this.touch.dragging = false
-        this.unbindEvents()
-      }, 100)
-    },
-
-    // Get the cursor position relative to the splitpane container.
-    getCurrentMouseDrag (event) {
-      const rect = this.container.getBoundingClientRect()
-      const { clientX, clientY } = ('ontouchstart' in window && event.touches)
-        ? event.touches[0]
-        : event
-      return {
-        x: clientX - rect.left,
-        y: clientY - rect.top
-      }
-    },
-
-    // Returns the drag percentage of the splitter relative to the 2 panes it's inbetween.
-    // if the sum of size of the 2 cells is 60%, the dragPercentage range will be 0 to 100% of this 60%.
-    getCurrentDragPercentage (drag) {
-      drag = drag[this.horizontal ? 'y' : 'x']
-      // In the code bellow 'size' refers to 'width' for vertical and 'height' for horizontal layout.
-      const containerSize = this.container[this.horizontal ? 'clientHeight' : 'clientWidth']
-      return drag * 100 / containerSize
+      splitter.unbindEvents(this.onMouseMove, this.onMouseUp)
     },
 
     moveSplitter (event) {
-      const dragPercentage = this.getCurrentDragPercentage(this.getCurrentMouseDrag(event))
-      const paneBefore = this.paneBefore
-      const paneAfter = this.paneAfter
+      const dragPercentage = splitter
+        .getCurrentDragPercentage(event, this.container, this.horizontal)
 
-      const paneBeforeMaxReached = paneBefore.max < 100 && (dragPercentage >= paneBefore.max)
-      const paneAfterMaxReached = paneAfter.max < 100 && (dragPercentage <= 100 - paneAfter.max)
-
-      const dir = this.horizontal ? 'top' : 'left'
+      const paneBeforeMax = this.paneBefore.max
+      const paneAfterMax = this.paneAfter.max
 
       // Prevent dragging beyond pane max.
-      if (paneBeforeMaxReached || paneAfterMaxReached) {
-        if (paneBeforeMaxReached) {
-          this.$set(this.movableSplitter, dir, paneBefore.max)
-        } else {
-          this.$set(this.movableSplitter, dir, Math.max(100 - paneAfter.max, 0))
-        }
-      } else {
-        this.$set(this.movableSplitter, dir, Math.min(Math.max(dragPercentage, 0), paneBefore.max))
-      }
+      const offset = splitter.calculateOffset(paneBeforeMax, paneAfterMax, dragPercentage)
+      const dir = this.horizontal ? 'top' : 'left'
+      this.$set(this.movableSplitter, dir, offset)
     },
-    togglePane (toggledPane) {
-      const pane = toggledPane === 'before' ? this.paneBefore : this.paneAfter
+
+    togglePane (pane) {
       if (pane.size > 0) {
         this.beforeMinimising.before = this.paneBefore.size
         this.beforeMinimising.after = this.paneAfter.size
         pane.size = 0
-        const otherPane = toggledPane === 'before' ? this.paneAfter : this.paneBefore
+        const otherPane = pane === this.paneBefore ? this.paneAfter : this.paneBefore
         otherPane.size = 100 - pane.size
       } else {
         this.paneBefore.size = this.beforeMinimising.before
@@ -265,11 +208,11 @@ export default {
   position: relative;
 }
 
-.splitpanes--vertical {flex-direction: row;}
-.splitpanes--horizontal {flex-direction: column;}
-.splitpanes--dragging * {user-select: none;}
+.splitpanes-vertical {flex-direction: row;}
+.splitpanes-horizontal {flex-direction: column;}
+.splitpanes-dragging * {user-select: none;}
 
-.splitpanes__pane {
+.splitpanes-pane {
   width: 100%;
   height: 100%;
   overflow: auto;
@@ -277,16 +220,16 @@ export default {
 
 /* Splitter */
 
-.splitpanes--vertical > .splitpanes__splitter,
-.splitpanes--vertical.splitpanes--dragging {
+.splitpanes-vertical > .splitpanes-splitter,
+.splitpanes-vertical.splitpanes-dragging {
   cursor: col-resize;
 }
-.splitpanes--horizontal > .splitpanes__splitter,
-.splitpanes--horizontal.splitpanes--dragging {
+.splitpanes-horizontal > .splitpanes-splitter,
+.splitpanes-horizontal.splitpanes-dragging {
   cursor: row-resize;
 }
 
-.splitpanes__splitter {
+.splitpanes-splitter {
   touch-action: none;
   background-color: var(--color-bg-light);
   box-sizing: border-box;
@@ -295,12 +238,12 @@ export default {
   z-index: 1;
 }
 
-.splitpanes--horizontal > .splitpanes__splitter {
+.splitpanes-horizontal > .splitpanes-splitter {
   border-top: 1px solid var(--color-border-light);
   border-bottom: 1px solid var(--color-border-light);
 }
 
-.splitpanes--vertical > .splitpanes__splitter {
+.splitpanes-vertical > .splitpanes-splitter {
   border-left: 1px solid var(--color-border-light);
   border-right: 1px solid var(--color-border-light);
 }
@@ -310,15 +253,15 @@ export default {
   background-color:rgba(162, 177, 198, 0.5);
 }
 
-.splitpanes--vertical > .splitpanes__splitter,
-.splitpanes--vertical > .movable-splitter {
+.splitpanes-vertical > .splitpanes-splitter,
+.splitpanes-vertical > .movable-splitter {
   width: 8px;
   z-index: 5;
   height: 100%
 }
 
-.splitpanes--horizontal > .splitpanes__splitter,
-.splitpanes--horizontal > .movable-splitter {
+.splitpanes-horizontal > .splitpanes-splitter,
+.splitpanes-horizontal > .movable-splitter {
   height: 8px;
   width: 100%;
   z-index: 5;
@@ -332,11 +275,11 @@ export default {
   display: flex;
 }
 
-.splitpanes--vertical > .splitpanes__splitter .toggle-btns {
+.splitpanes-vertical > .splitpanes-splitter .toggle-btns {
   flex-direction: column;
 }
 
-.splitpanes--horizontal > .splitpanes__splitter .toggle-btns {
+.splitpanes-horizontal > .splitpanes-splitter .toggle-btns {
   flex-direction: row;
 }
 
@@ -349,12 +292,12 @@ export default {
   cursor: pointer;
 }
 
-.splitpanes--vertical > .splitpanes__splitter .toggle-btn {
+.splitpanes-vertical > .splitpanes-splitter .toggle-btn {
   height: 49px;
   width: 8px;
 }
 
-.splitpanes--horizontal > .splitpanes__splitter .toggle-btn {
+.splitpanes-horizontal > .splitpanes-splitter .toggle-btn {
   width: 49px;
   height: 8px;
 }
@@ -365,20 +308,20 @@ export default {
   left: 50%;
 }
 
-.splitpanes--horizontal > .splitpanes__splitter .toggle-btns.both .toggle-btn:first-child {
+.splitpanes-horizontal > .splitpanes-splitter .toggle-btns.both .toggle-btn:first-child {
   border-radius: var(--border-radius-small) 0 0 var(--border-radius-small);
 }
 
-.splitpanes--horizontal > .splitpanes__splitter .toggle-btns.both .toggle-btn:last-child {
+.splitpanes-horizontal > .splitpanes-splitter .toggle-btns.both .toggle-btn:last-child {
   border-radius: 0 var(--border-radius-small) var(--border-radius-small) 0;
   margin-left: -1px;
 }
 
-.splitpanes--vertical > .splitpanes__splitter .toggle-btns.both .toggle-btn:first-child {
+.splitpanes-vertical > .splitpanes-splitter .toggle-btns.both .toggle-btn:first-child {
   border-radius: var(--border-radius-small) var(--border-radius-small) 0 0;
 }
 
-.splitpanes--vertical > .splitpanes__splitter .toggle-btns.both .toggle-btn:last-child {
+.splitpanes-vertical > .splitpanes-splitter .toggle-btns.both .toggle-btn:last-child {
   border-radius: 0 0 var(--border-radius-small) var(--border-radius-small);
   margin-top: -1px;
 }
diff --git a/src/splitter.js b/src/splitter.js
new file mode 100644
index 0000000..3c7032f
--- /dev/null
+++ b/src/splitter.js
@@ -0,0 +1,54 @@
+export default {
+  bindEvents (onMouseMove, onMouseUp) {
+    // Passive: false to prevent scrolling while touch dragging.
+    document.addEventListener('mousemove', onMouseMove, { passive: false })
+    document.addEventListener('mouseup', onMouseUp)
+
+    if ('ontouchstart' in window) {
+      document.addEventListener('touchmove', onMouseMove, { passive: false })
+      document.addEventListener('touchend', onMouseUp)
+    }
+  },
+
+  unbindEvents (onMouseMove, onMouseUp) {
+    document.removeEventListener('mousemove', onMouseMove, { passive: false })
+    document.removeEventListener('mouseup', onMouseUp)
+
+    if ('ontouchstart' in window) {
+      document.removeEventListener('touchmove', onMouseMove, { passive: false })
+      document.removeEventListener('touchend', onMouseUp)
+    }
+  },
+
+  // Get the cursor position relative to the splitpane container.
+  getCurrentMouseDrag (event, container) {
+    const rect = container.getBoundingClientRect()
+    const { clientX, clientY } = ('ontouchstart' in window && event.touches)
+      ? event.touches[0]
+      : event
+    return {
+      x: clientX - rect.left,
+      y: clientY - rect.top
+    }
+  },
+
+  // Returns the drag percentage of the splitter relative to the 2 panes it's inbetween.
+  getCurrentDragPercentage (event, container, isHorisontal) {
+    let drag = this.getCurrentMouseDrag(event, container)
+    drag = drag[isHorisontal ? 'y' : 'x']
+    const containerSize = container[isHorisontal ? 'clientHeight' : 'clientWidth']
+    return drag * 100 / containerSize
+  },
+
+  calculateOffset (paneBeforeMax, paneAfterMax, dragPercentage) {
+    const paneBeforeMaxReached = paneBeforeMax < 100 && (dragPercentage >= paneBeforeMax)
+    const paneAfterMaxReached = paneAfterMax < 100 && (dragPercentage <= 100 - paneAfterMax)
+
+    // Prevent dragging beyond pane max.
+    if (paneBeforeMaxReached || paneAfterMaxReached) {
+      return paneBeforeMaxReached ? paneBeforeMax : Math.max(100 - paneAfterMax, 0)
+    } else {
+      return Math.min(Math.max(dragPercentage, 0), paneBeforeMax)
+    }
+  }
+}