From f645b96ee83195c07ab23209e7d77473fbf1ef3d Mon Sep 17 00:00:00 2001
From: cagataycivici <cagatay.civici@gmail.com>
Date: Thu, 1 Aug 2019 23:56:05 +0300
Subject: [PATCH] Checkbox selection for Tree

---
 src/components/tree/Tree.vue         |  74 ++++++++++++++-----
 src/components/tree/TreeNode.vue     | 104 +++++++++++++++++++++++++--
 src/views/tree/TreeSelectionDemo.vue |   6 +-
 3 files changed, 155 insertions(+), 29 deletions(-)

diff --git a/src/components/tree/Tree.vue b/src/components/tree/Tree.vue
index c9cd119b8..f5e34f8da 100644
--- a/src/components/tree/Tree.vue
+++ b/src/components/tree/Tree.vue
@@ -3,7 +3,7 @@
         <ul class="p-tree-container" role="tree">
             <TreeNode v-for="node of value" :key="node.key" :node="node"
                 :expandedKeys="d_expandedKeys" @node-toggle="onNodeToggle" @node-click="onNodeClick"
-                :selectionMode="selectionMode" :selectionKeys="selectionKeys"></TreeNode>
+                :selectionMode="selectionMode" :selectionKeys="selectionKeys" @checkbox-change="onCheckboxChange"></TreeNode>
         </ul>
     </div>
 </template>
@@ -33,14 +33,6 @@ export default {
             type: Boolean,
             default: true
         },
-        propagateSelectionDown: {
-            type: Boolean,
-            default: true
-        },
-        propagateSelectionUp: {
-            type: Boolean,
-            default: true
-        },
         loading: {
             type: Boolean,
             default: false
@@ -78,19 +70,20 @@ export default {
         },
         onNodeClick(event) {
             if (this.selectionMode != null && event.node.selectable !== false) {
-                let _selectionKeys;
-
-                if (this.isCheckboxSelectionMode()) {
-
-                }
-                else {
-                    const metaSelection = event.nodeTouched ? false : this.metaKeySelection;
-                    _selectionKeys = metaSelection ? this.handleSelectionWithMetaKey(event) : this.handleSelectionWithoutMetaKey(event);
-                }
+                const metaSelection = event.nodeTouched ? false : this.metaKeySelection;
+                const _selectionKeys = metaSelection ? this.handleSelectionWithMetaKey(event) : this.handleSelectionWithoutMetaKey(event);
 
                 this.$emit('update:selectionKeys', _selectionKeys);
             }
         },
+        onCheckboxChange(event) {
+            this.$emit('update:selectionKeys', event.selectionKeys);
+
+            if (event.check)
+                this.$emit('node-select', event.node);
+            else
+                this.$emit('node-unselect', event.node);
+        },
         handleSelectionWithMetaKey(event) {
             const originalEvent = event.originalEvent;
             const node = event.node;
@@ -156,6 +149,46 @@ export default {
 
             return _selectionKeys;
         },
+        /*handleCheckboxSelection(event) {
+            const node = event.node;
+            const checked = this.isChecked(node);
+            let _selectionKeys = this.selectionKeys ? {...this.selectionKeys} : {};    
+
+            if (checked) {
+                if (this.propagateSelectionDown)
+                    this.propagateDown(node, false, _selectionKeys);
+                else
+                    delete _selectionKeys[node.key];
+
+                if (this.propagateSelectionUp && this.props.onPropagateUp) {
+                    this.props.onPropagateUp({
+                        originalEvent: event,
+                        check: false,
+                        selectionKeys: selectionKeys
+                    });
+                }
+
+                this.$emit('node-unselect', node);
+            }
+            else {
+                if (this.props.propagateSelectionDown)
+                    this.propagateDown(this.props.node, true, selectionKeys);
+                else 
+                    selectionKeys[this.props.node.key] = {checked: true};
+
+                    if (this.props.propagateSelectionUp && this.props.onPropagateUp) {
+                        this.props.onPropagateUp({
+                            originalEvent: event,
+                            check: true,
+                            selectionKeys: selectionKeys
+                        });
+                    }
+
+                this.$emit('node-select', node);
+            }
+
+            return _selectionKeys;
+        },*/
         isCheckboxSelectionMode() {
             return this.selectionMode === 'checkbox';
         },
@@ -167,7 +200,10 @@ export default {
         },
         isSelected(node) {
             return (this.selectionMode && this.selectionKeys) ? this.selectionKeys[node.key] === true : false;
-        }
+        },
+        isChecked(node) {
+            return this.selectionKeys ? this.selectionKeys[node.key] && this.selectionKeys[node.key].checked: false;
+        },
     },
     computed: {
         containerClass() {
diff --git a/src/components/tree/TreeNode.vue b/src/components/tree/TreeNode.vue
index e54369ba7..cf19d7f1c 100644
--- a/src/components/tree/TreeNode.vue
+++ b/src/components/tree/TreeNode.vue
@@ -5,13 +5,19 @@
             <span class="p-tree-toggler p-unselectable-text p-link" @click="toggle">
                 <span :class="toggleIcon"></span>
             </span>
+            <div class="p-checkbox p-component" v-if="checkboxMode">
+                <div :class="checkboxClass">
+                    <span :class="checkboxIcon"></span>
+                </div>
+            </div>
             <span :class="icon"></span>
             <span class="p-treenode-label">{{node.label}}</span>
         </div>
         <ul class="p-treenode-children" role="group" v-if="hasChildren && expanded">
             <sub-treenode v-for="childNode of node.children" :key="childNode.key" :node="childNode"
                 :expandedKeys="expandedKeys" @node-toggle="onChildNodeToggle" @node-click="onChildNodeClick"
-                :selectionMode="selectionMode" :selectionKeys="selectionKeys"></sub-treenode>
+                :selectionMode="selectionMode" :selectionKeys="selectionKeys" 
+                @checkbox-change="propagateUp"></sub-treenode>
         </ul>
     </li>
 </template>
@@ -52,11 +58,17 @@ export default {
                 return;
             }
 
-            this.$emit('node-click', {
-                originalEvent: event,
-                nodeTouched: this.nodeTouched,
-                node: this.node
-            });
+            if (this.isCheckboxSelectionMode()) {
+                this.toggleCheckbox();
+            }
+            else {
+                this.$emit('node-click', {
+                    originalEvent: event,
+                    nodeTouched: this.nodeTouched,
+                    node: this.node
+                });
+            }
+
             this.nodeTouched = false;
         },
         onChildNodeClick(event) {
@@ -125,6 +137,66 @@ export default {
                 break;
             }
         },
+        toggleCheckbox() {
+            let _selectionKeys = this.selectionKeys ? {...this.selectionKeys} : {};   
+            const _check = !this.checked;
+
+            this.propagateDown(this.node, _check, _selectionKeys);
+
+            this.$emit('checkbox-change', {
+                node: this.node,
+                check: _check,
+                selectionKeys: _selectionKeys
+            });
+        },
+        propagateDown(node, check, selectionKeys) {
+            if (check)
+                selectionKeys[node.key] = {checked: true, partialChecked: false};
+            else
+                delete selectionKeys[node.key];
+
+            if (node.children && node.children.length) {
+                for (let child of node.children) {
+                    this.propagateDown(child, check, selectionKeys);
+                }
+            }
+        },
+        propagateUp(event) {
+            let check = event.check;
+            let _selectionKeys = {...event.selectionKeys};
+            let checkedChildCount = 0;
+            let childPartialSelected = false;
+            
+            for(let child of this.node.children) {
+                if(_selectionKeys[child.key] && _selectionKeys[child.key].checked)
+                    checkedChildCount++;
+                else if(_selectionKeys[child.key] && _selectionKeys[child.key].partialChecked)
+                    childPartialSelected = true;
+            }
+
+            if(check && checkedChildCount === this.node.children.length) {
+                _selectionKeys[this.node.key] = {checked: true, partialChecked: false};
+            }
+            else {
+                if (!check) {
+                    delete _selectionKeys[this.node.key];
+                }
+
+                if(childPartialSelected || (checkedChildCount > 0 && checkedChildCount !== this.node.children.length))
+                    _selectionKeys[this.node.key] = {checked: false, partialChecked: true};
+                else
+                    _selectionKeys[this.node.key] = {checked: false, partialChecked: false};
+            }
+
+            this.$emit('checkbox-change', {
+                node: event.node,
+                check: event.check,
+                selectionKeys: _selectionKeys
+            }); 
+        },
+        onChildCheckboxChange(event) {
+            this.$emit('checkbox-change', event);
+        },
         findNextSiblingOfAncestor(nodeElement) {
             let parentNodeElement = this.getParentNodeElement(nodeElement);
             if (parentNodeElement) {
@@ -155,6 +227,9 @@ export default {
         },
         focusNode(element) {
             element.children[0].focus();
+        },
+        isCheckboxSelectionMode() {
+            return this.selectionMode === 'checkbox';
         }
     },
     computed: {
@@ -179,7 +254,7 @@ export default {
         contentClass() {
             return ['p-treenode-content', {
                 'p-treenode-selectable': this.selectable,
-                'p-highlight': this.selected
+                'p-highlight': this.checkboxMode ? this.checked : this.selected
             }];
         },
         icon() {
@@ -190,6 +265,21 @@ export default {
                 'pi-caret-down': this.expanded,
                 'pi-caret-right': !this.expanded
             }];
+        },
+        checkboxClass() {
+            return ['p-checkbox-box', {'p-highlight': this.checked}];
+        },
+        checkboxIcon() {
+            return ['p-checkbox-icon p-c', {'pi pi-check': this.checked, 'pi pi-minus': this.partialChecked}];
+        },
+        checkboxMode() {
+            return this.selectionMode === 'checkbox' && this.node.selectable !== false;
+        },
+        checked() {
+            return this.selectionKeys ? this.selectionKeys[this.node.key] && this.selectionKeys[this.node.key].checked: false;
+        },
+        partialChecked() {
+            return this.selectionKeys ? this.selectionKeys[this.node.key] && this.selectionKeys[this.node.key].partialChecked: false;
         }
     }
 }
diff --git a/src/views/tree/TreeSelectionDemo.vue b/src/views/tree/TreeSelectionDemo.vue
index 65926ffae..5094104b7 100644
--- a/src/views/tree/TreeSelectionDemo.vue
+++ b/src/views/tree/TreeSelectionDemo.vue
@@ -12,15 +12,15 @@
         <div class="content-section implementation">
             <h3>Single Selection</h3>
             <Tree :value="nodes" selectionMode="single" :selectionKeys.sync="selectedKey"></Tree>
-            {{selectedKey}}
 
             <h3>Multiple Selection with MetaKey</h3>
             <Tree :value="nodes" selectionMode="multiple" :selectionKeys.sync="selectedKeys1"></Tree>
-            {{selectedKeys1}}
 
             <h3>Multiple Selection without MetaKey</h3>
             <Tree :value="nodes" selectionMode="multiple" :selectionKeys.sync="selectedKeys2" :metaKeySelection="false"></Tree>
-            {{selectedKeys2}}
+
+            <h3>Checkbox Selection</h3>
+            <Tree :value="nodes" selectionMode="checkbox" :selectionKeys.sync="selectedKeys3"></Tree>
         </div>
 
         <TreeDoc />