Implement selecting one or multiple nodes by dragging

src/JSONEditor.scss

@@ -64,8 +64,7 @@
     flex: 1;
     overflow: auto;
 
-    .bottom {
-      height: $input-padding;
-    }
+    //display: flex;
+    //flex-direction: column;
   }
 }

src/JSONEditor.svelte

@@ -11,6 +11,7 @@
   import { faSearch, faUndo, faRedo } from '@fortawesome/free-solid-svg-icons'
   import { createHistory } from './history.js'
   import Node from './JSONNode.svelte'
+  import { expandSelection } from './selection.js'
   import {
     existsIn,
     getIn,
@@ -36,6 +37,19 @@
 
   export let doc = {}
   let state = undefined
+  let selection = null
+  let selectionMap = {}
+
+  $: {
+    selectionMap = {}
+    if (selection != null) {
+      selection.forEach(path => {
+        selectionMap[compileJSONPointer(path)] = true
+      })
+    }
+  }
+
+  $: console.log('selectionMap', selectionMap)
 
   export let onChangeJson = () => {}
 
@@ -257,6 +271,14 @@
     state = setIn(state, path.concat(STATE_LIMIT), limit)
   }
 
+  function handleSelect (anchorPath, focusPath) {
+    if (anchorPath && focusPath) {
+      selection = expandSelection(doc, state, anchorPath, focusPath)
+    } else {
+      selection = null
+    }
+  }
+
   /**
    * Expand all nodes on given path
    * @param {Path} path
@@ -373,8 +395,9 @@
       onPatch={handlePatch}
       onExpand={handleExpand}
       onLimit={handleLimit}
+      onSelect={handleSelect}
+      selectionMap={selectionMap}
     />
-    <div class='bottom'></div>
   </div>
 </div>
 

src/JSONNode.scss

@@ -5,6 +5,18 @@
   font-size: $font-size;
   color: $black;
 
+  &.root {
+    min-height: 100%;
+    padding-bottom: $input-padding;
+    box-sizing: border-box;
+  }
+
+  &.selected .header,
+  &.selected .contents,
+  &.selected .footer {
+    background-color: $selection-background;
+  }
+
   .header {
     position: relative;
   }
@@ -27,6 +39,7 @@
   }
 
   .footer {
+    display: inline-block;
     padding-left: $line-height + $input-padding; // must be the same as the width of the expand button
   }
 }
@@ -86,10 +99,6 @@
   }
 }
 
-.items,
-.props {
-  padding-left: $indentation-width;
-}
 .value {
 
   &.string {
@@ -125,8 +134,6 @@
 }
 
 div.limit {
-  margin-left: $indentation-width;
-
   button {
     background: none;
     border: none;

src/JSONNode.svelte

@@ -1,18 +1,21 @@
 <script>
-  import { debounce, initial } from 'lodash-es'
+  import { debounce, initial, isEqual } from 'lodash-es'
   import {
-    DEBOUNCE_DELAY, DEFAULT_LIMIT,
-    STATE_EXPANDED, STATE_LIMIT, STATE_PROPS,
+    DEBOUNCE_DELAY,
+    DEFAULT_LIMIT,
+    STATE_EXPANDED,
+    STATE_LIMIT,
+    STATE_PROPS,
     STATE_SEARCH_PROPERTY,
-    STATE_SEARCH_VALUE
+    STATE_SEARCH_VALUE,
+    INDENTATION_WIDTH
   } from './constants.js'
+  import { singleton } from './singleton.js'
   import { getPlainText, setPlainText } from './utils/domUtils.js'
   import Icon from 'svelte-awesome'
   import { faCaretDown, faCaretRight } from '@fortawesome/free-solid-svg-icons'
   import classnames from 'classnames'
-  import { findUniqueName } from './utils/stringUtils.js'
   import { isUrl, stringConvert, valueType } from './utils/typeUtils'
-  import { updateProps } from './utils/updateProps.js'
   import { compileJSONPointer } from './utils/jsonPointer'
 
   export let key = undefined // only applicable for object properties
@@ -23,6 +26,8 @@
   export let onPatch
   export let onExpand
   export let onLimit
+  export let onSelect
+  export let selectionMap
 
   $: expanded = state && state[STATE_EXPANDED]
   $: limit = state && state[STATE_LIMIT]
@@ -67,6 +72,10 @@
     }
   }
 
+  function getIndentationStyle(level) {
+    return `margin-left: ${level * INDENTATION_WIDTH}px`
+  }
+
   function getValueClass (value, searchResult) {
     const type = valueType (value)
 
@@ -182,11 +191,73 @@
   function handleShowMore () {
     onLimit(path, (Math.round(limit / DEFAULT_LIMIT) + 1) * DEFAULT_LIMIT)
   }
+
+  function handleMouseDown (event) {
+    // unselect existing selection on mouse down if any
+    if (singleton.selectionAnchor != null && singleton.selectionFocus != null) {
+      singleton.selectionAnchor = null
+      singleton.selectionFocus = null
+      onSelect(null, null)
+    }
+
+    // check if the mouse down is not happening in the key or value input fields
+    if (event.target.contentEditable !== 'true') {
+      // initialize dragging a selection
+      singleton.mousedown = true
+      singleton.selectionAnchor = path
+      singleton.selectionFocus = null
+      event.stopPropagation()
+    }
+
+    // we attache the mouse up event listener to the global document,
+    // so we will not miss if the mouse up is happening outside of the editor
+    document.addEventListener('mouseup', handleMouseUp)
+  }
+
+  function handleMouseMove (event) {
+    if (singleton.mousedown) {
+      event.preventDefault()
+      event.stopPropagation()
+
+      if (singleton.selectionFocus == null) {
+        // First move event, no selection yet.
+        // Clear the default selection of the browser
+        if (window.getSelection) {
+          window.getSelection().empty()
+        }
+      }
+
+      if (!isEqual(path, singleton.selectionFocus)) {
+        singleton.selectionFocus = path
+        onSelect(singleton.selectionAnchor, singleton.selectionFocus)
+      }
+    }
+  }
+
+  function handleMouseUp (event) {
+    if (singleton.mousedown) {
+      event.preventDefault()
+      event.stopPropagation()
+
+      singleton.mousedown = false
+    }
+
+    document.removeEventListener('mouseup', handleMouseUp)
+  }
+
+  // FIXME: this is not efficient. Create a nested object with the selection and pass that
+  $: selected = selectionMap[compileJSONPointer(path)] === true
 </script>
 
-<div class='json-node'>
+<div
+  class='json-node'
+  class:root={path.length === 0}
+  class:selected={selected}
+  on:mousedown={handleMouseDown}
+  on:mousemove={handleMouseMove}
+>
   {#if type === 'array'}
-    <div class='header'>
+    <div class='header' style={getIndentationStyle(path.length)}>
       <button
         class='expand'
         on:click={toggleExpand}
@@ -230,20 +301,22 @@
             onPatch={onPatch}
             onExpand={onExpand}
             onLimit={onLimit}
+            onSelect={onSelect}
+            selectionMap={selectionMap}
           />
         {/each}
         {#if limited}
-          <div class='limit'>
+          <div class="limit" style={getIndentationStyle(path.length + 2)}>
             (showing {limit} of {value.length} items <button on:click={handleShowMore}>show more</button> <button on:click={handleShowAll}>show all</button>)
           </div>
         {/if}
       </div>
-      <div class="footer">
+      <div class="footer" style={getIndentationStyle(path.length)}>
         <span class="delimiter">]</span>
       </div>
     {/if}
   {:else if type === 'object'}
-    <div class='header'>
+    <div class='header' style={getIndentationStyle(path.length)}>
       <button
         class='expand'
         on:click={toggleExpand}
@@ -287,15 +360,17 @@
             onPatch={onPatch}
             onExpand={onExpand}
             onLimit={onLimit}
+            onSelect={onSelect}
+            selectionMap={selectionMap}
           />
         {/each}
       </div>
-      <div class="footer">
+      <div class="footer" style={getIndentationStyle(path.length)}>
         <span class="delimiter">}</span>
       </div>
     {/if}
   {:else}
-    <div class="contents">
+    <div class="contents" style={getIndentationStyle(path.length)}>
       {#if typeof key === 'string'}
         <div
           class={keyClass}

src/constants.js

@@ -8,3 +8,5 @@ export const STATE_SEARCH_VALUE = Symbol('search:value')
 export const SCROLL_DURATION = 300 // ms
 export const DEBOUNCE_DELAY = 300
 export const DEFAULT_LIMIT = 100
+
+export const INDENTATION_WIDTH = 18 // pixels IMPORTANT: keep in sync with sass constant $indentation-width

src/selection.js

@@ -0,0 +1,83 @@
+import { isEqual } from 'lodash-es'
+import { STATE_PROPS } from './constants.js'
+import { getIn } from './utils/immutabilityHelpers.js'
+import { isObject } from './utils/typeUtils.js'
+
+/**
+ * Expand a selection start and end into an array containing all paths
+ * between (and including) start and end
+ *
+ * @param {JSON} doc
+ * @param {JSON} state
+ * @param {Path} anchorPath
+ * @param {Path} focusPath
+ * @return {Path[]} selection
+ */
+export function expandSelection (doc, state, anchorPath, focusPath) {
+  if (isEqual(anchorPath, focusPath)) {
+    // just a single node
+    return [ anchorPath ]
+  } else {
+    // multiple nodes
+    let sharedPath = findSharedPath(anchorPath, focusPath)
+
+    if (anchorPath.length === sharedPath.length || focusPath.length === sharedPath.length) {
+      // a parent and a child, like ['arr', 1] and ['arr']
+      return [ sharedPath ]
+    }
+
+    const anchorProp = anchorPath[sharedPath.length]
+    const focusProp = focusPath[sharedPath.length]
+    const value = getIn(doc, sharedPath)
+
+    if (isObject(value)) {
+      const props = getIn(state, sharedPath.concat(STATE_PROPS))
+      const anchorIndex = props.findIndex(prop => prop.key === anchorProp)
+      const focusIndex = props.findIndex(prop => prop.key === focusProp)
+
+      if (anchorIndex !== -1 && focusIndex !== -1) {
+        const startIndex = Math.min(anchorIndex, focusIndex)
+        const endIndex = Math.max(anchorIndex, focusIndex)
+        const paths = []
+
+        for (let i = startIndex; i <= endIndex; i++) {
+          paths.push(sharedPath.concat(props[i].key))
+        }
+
+        return paths
+      }
+    }
+
+    if (Array.isArray(value)) {
+      const startIndex = Math.min(anchorProp, focusProp)
+      const endIndex = Math.max(anchorProp, focusProp)
+      const paths = []
+
+      for (let i = startIndex; i <= endIndex; i++) {
+        paths.push(sharedPath.concat(i))
+      }
+
+      return paths
+    }
+  }
+
+  // should never happen
+  return []
+}
+
+/**
+ * Find the common path of two paths.
+ * For example findCommonRoot(['arr', '1', 'name'], ['arr', '1', 'address', 'contact']) returns ['arr', '1']
+ * @param {Path} path1
+ * @param {Path} path2
+ * @return {Path}
+ */
+// TODO: write unit tests for findSharedPath
+export function findSharedPath (path1, path2) {
+  let i = 0;
+  while (i < path1.length && path1[i] === path2[i]) {
+    i++;
+  }
+
+  return path1.slice(0, i)
+}

src/selection.test.js

@@ -0,0 +1,68 @@
+import assert from 'assert'
+import { expandSelection } from './selection.js'
+import { syncState } from './utils/syncState.js'
+
+describe ('selection', () => {
+  const doc = {
+    "obj": {
+      "arr": [1,2, {"first":3,"last":4}]
+    },
+    "str": "hello world",
+    "nill": null,
+    "bool": false
+  }
+  const state = syncState(doc, undefined, [], () => true)
+
+  it('should expand a selection (object)', () => {
+    const start = ['obj', 'arr', '2', 'last']
+    const end = ['nill']
+
+    const actual = expandSelection(doc, state, start, end)
+    assert.deepStrictEqual(actual, [
+      ['obj'],
+      ['str'],
+      ['nill']
+    ])
+  })
+
+  it('should expand a selection (array)', () => {
+    const start = ['obj', 'arr', 1]
+    const end = ['obj', 'arr', 0] // note the "wrong" order of start and end
+
+    const actual = expandSelection(doc, state, start, end)
+    assert.deepStrictEqual(actual, [
+      ['obj', 'arr', 0],
+      ['obj', 'arr', 1]
+    ])
+  })
+
+  it('should expand a selection (array) (2)', () => {
+    const start = ['obj', 'arr', 1] // child
+    const end = ['obj', 'arr'] // parent
+
+    const actual = expandSelection(doc, state, start, end)
+    assert.deepStrictEqual(actual, [
+      ['obj', 'arr']
+    ])
+  })
+
+  it('should expand a selection (value)', () => {
+    const start = ['obj', 'arr', 2, 'first']
+    const end = ['obj', 'arr', 2, 'first']
+
+    const actual = expandSelection(doc, state, start, end)
+    assert.deepStrictEqual(actual, [
+      ['obj', 'arr', 2, 'first']
+    ])
+  })
+
+  it('should expand a selection (value)', () => {
+    const start = ['obj', 'arr']
+    const end = ['obj', 'arr']
+
+    const actual = expandSelection(doc, state, start, end)
+    assert.deepStrictEqual(actual, [
+      ['obj', 'arr']
+    ])
+  })
+})

src/singleton.js

@@ -0,0 +1,5 @@
+export const singleton = {
+  mousedown: false,
+  selectionAnchor: null, // Path
+  selectionFocus: null // Path
+}

src/styles.scss

@@ -24,12 +24,14 @@ $error-border-color: #ffd700;
 $gray: #9d9d9d;
 $gray-icon: $gray;
 $light-gray: #c0c0c0;
+$selection-background: #e0e0e0;
 
 $line-height: 18px;
-$indentation-width: 18px;
+$indentation-width: 18px; // IMPORTANT: keep in sync with js constant INDENTATION_WIDTH
 $menu-button-size: 32px;
 $input-padding: 5px;
 $search-box-offset: 10px;
 $border-radius: 3px;
 
 $menu-padding: 5px;
+$bottom-height: 5px;

src/utils/syncState.test.js

@@ -24,9 +24,9 @@ describe('syncState', () => {
     const expectedState = {}
     expectedState[STATE_EXPANDED] = true
     expectedState[STATE_PROPS] =  [
-      { 'id': '1', 'key': 'array' },
-      { 'id': '2', 'key': 'object' },
-      { 'id': '3', 'key': 'value' }
+      { 'id': state[STATE_PROPS][0].id, 'key': 'array' },
+      { 'id': state[STATE_PROPS][1].id, 'key': 'object' },
+      { 'id': state[STATE_PROPS][2].id, 'key': 'value' }
     ]
     expectedState.array = []
     expectedState.array[STATE_EXPANDED] = true
@@ -34,13 +34,13 @@ describe('syncState', () => {
     expectedState.array[2] = {}
     expectedState.array[2][STATE_EXPANDED] = false
     expectedState.array[2][STATE_PROPS] = [
-      { 'id': '4', 'key': 'c' } // FIXME: props should not be created because node is not expande
+      { 'id': state.array[2][STATE_PROPS][0].id, 'key': 'c' } // FIXME: props should not be created because node is not expanded
     ]
     expectedState.object = {}
     expectedState.object[STATE_EXPANDED] = true
     expectedState.object[STATE_PROPS] =  [
-      { 'id': '5', 'key': 'a' },
-      { 'id': '6', 'key': 'b' }
+      { 'id': state.object[STATE_PROPS][0].id, 'key': 'a' },
+      { 'id': state.object[STATE_PROPS][1].id, 'key': 'b' }
     ]
 
     assert.deepStrictEqual(state, expectedState)