From 537bf17b7d3e1a32d73223a947d9ebed425d2285 Mon Sep 17 00:00:00 2001
From: CoryDCode <corydiers@google.com>
Date: Thu, 30 Mar 2017 11:31:31 -0700
Subject: [PATCH] Adding the remove variable modal and functionality to
 accessible Blockly. (#1011)

---
 accessible/app.component.js                   |   6 +-
 accessible/field-segment.component.js         |  16 +-
 accessible/variable-modal.service.js          |  23 ++-
 accessible/variable-remove-modal.component.js | 164 ++++++++++++++++++
 ....js => variable-rename-modal.component.js} |   8 +-
 core/field.js                                 |   7 +
 core/field_variable.js                        |   6 +
 core/workspace.js                             |  31 ++--
 demos/accessible/index.html                   |   3 +-
 9 files changed, 240 insertions(+), 24 deletions(-)
 create mode 100644 accessible/variable-remove-modal.component.js
 rename accessible/{variable-modal.component.js => variable-rename-modal.component.js} (92%)

diff --git a/accessible/app.component.js b/accessible/app.component.js
index 737d39267..775f5411f 100644
--- a/accessible/app.component.js
+++ b/accessible/app.component.js
@@ -38,7 +38,8 @@ blocklyApp.AppComponent = ng.core.Component({
 
     <blockly-block-options-modal></blockly-block-options-modal>
     <blockly-toolbox-modal></blockly-toolbox-modal>
-    <blockly-variable-modal></blockly-variable-modal>
+    <blockly-rename-variable-modal></blockly-rename-variable-modal>
+    <blockly-remove-variable-modal></blockly-remove-variable-modal>
 
     <label id="blockly-translate-button" aria-hidden="true" hidden>
       {{'BUTTON'|translate}}
@@ -51,7 +52,8 @@ blocklyApp.AppComponent = ng.core.Component({
     blocklyApp.BlockOptionsModalComponent,
     blocklyApp.SidebarComponent,
     blocklyApp.ToolboxModalComponent,
-    blocklyApp.VariableModalComponent,
+    blocklyApp.VariableRenameModalComponent,
+    blocklyApp.VariableRemoveModalComponent,
     blocklyApp.WorkspaceComponent
   ],
   pipes: [blocklyApp.TranslatePipe],
diff --git a/accessible/field-segment.component.js b/accessible/field-segment.component.js
index 71a025d22..4d528286b 100644
--- a/accessible/field-segment.component.js
+++ b/accessible/field-segment.component.js
@@ -75,6 +75,12 @@ blocklyApp.FieldSegmentComponent = ng.core.Component({
     this.dropdownOptions = [];
     this.rawOptions = [];
   }],
+  // Angular2 hook - called after initialization.
+  ngAfterContentInit: function() {
+    if (this.mainField) {
+      this.mainField.initModel();
+    }
+  },
   // Angular2 hook - called to check if the cached component needs an update.
   ngDoCheck: function() {
     if (this.isDropdown() && this.shouldBreakCache()) {
@@ -144,7 +150,12 @@ blocklyApp.FieldSegmentComponent = ng.core.Component({
   // Confirm a selection for dropdown fields.
   selectOption: function() {
     if (this.optionValue == Blockly.Msg.RENAME_VARIABLE) {
-      this.variableModalService.showModal_(this.mainField.getValue());
+      this.variableModalService.showRenameModal_(this.mainField.getValue());
+    }
+
+    if (this.optionValue ==
+        Blockly.Msg.DELETE_VARIABLE.replace('%1', this.mainField.getValue())) {
+      this.variableModalService.showRemoveModal_(this.mainField.getValue());
     }
   },
   // Sets the value on a dropdown input.
@@ -154,7 +165,8 @@ blocklyApp.FieldSegmentComponent = ng.core.Component({
       return;
     }
 
-    if (this.optionValue != Blockly.Msg.RENAME_VARIABLE) {
+    if (this.optionValue != Blockly.Msg.RENAME_VARIABLE && this.optionValue !=
+        Blockly.Msg.DELETE_VARIABLE.replace('%1', this.mainField.getValue())) {
       this.mainField.setValue(this.optionValue);
     }
 
diff --git a/accessible/variable-modal.service.js b/accessible/variable-modal.service.js
index 86b45bf25..812deb96d 100644
--- a/accessible/variable-modal.service.js
+++ b/accessible/variable-modal.service.js
@@ -30,20 +30,35 @@ blocklyApp.VariableModalService = ng.core.Class({
     }
   ],
   // Registers a hook to be called before the modal is shown.
-  registerPreShowHook: function(preShowHook) {
-    this.preShowHook = function(oldName) {
+  registerPreRenameShowHook: function(preShowHook) {
+    this.preRenameShowHook = function(oldName) {
       preShowHook(oldName);
     };
   },
+  registerPreRemoveShowHook: function(preShowHook) {
+    this.preRemoveShowHook = function(oldName, count) {
+      preShowHook(oldName, count);
+    };
+  },
   // Returns true if the variable modal is shown.
   isModalShown: function() {
     return this.modalIsShown;
   },
   // Show the variable modal.
-  showModal_: function(oldName) {
-    this.preShowHook(oldName);
+  showRenameModal_: function(oldName) {
+    this.preRenameShowHook(oldName);
     this.modalIsShown = true;
   },
+  // Show the variable modal.
+  showRemoveModal_: function(oldName) {
+    var count = blocklyApp.workspace.getVariableUses(oldName).length;
+    if (count > 1) {
+      this.preRemoveShowHook(oldName, count);
+      this.modalIsShown = true;
+    } else {
+      blocklyApp.workspace.deleteVariableInternal_(oldName);
+    }
+  },
   // Hide the variable modal.
   hideModal: function() {
     this.modalIsShown = false;
diff --git a/accessible/variable-remove-modal.component.js b/accessible/variable-remove-modal.component.js
new file mode 100644
index 000000000..be5ad43f3
--- /dev/null
+++ b/accessible/variable-remove-modal.component.js
@@ -0,0 +1,164 @@
+/**
+ * AccessibleBlockly
+ *
+ * Copyright 2017 Google Inc.
+ * https://developers.google.com/blockly/
+ *
+ * Licensed under the Apache License, Version 2.0 (the 'License');
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an 'AS IS' BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @fileoverview Component representing the variable remove modal.
+ *
+ * @author corydiers@google.com (Cory Diers)
+ */
+
+blocklyApp.VariableRemoveModalComponent = ng.core.Component({
+  selector: 'blockly-remove-variable-modal',
+  template: `
+    <div *ngIf="modalIsVisible"class="blocklyModalCurtain"
+         (click)="dismissModal()">
+      <!-- $event.stopPropagation() prevents the modal from closing when its
+      interior is clicked. -->
+      <div id="varModal" class="blocklyModal" role="alertdialog"
+           (click)="$event.stopPropagation()" tabindex="0"
+           aria-labelledby="variableModalHeading">
+          <form id="varForm">
+            <p id="label">Remove {{count}} instances of
+              "{{currentVariableName}}" variable?
+            </p>
+            <hr>
+            <button id="yesButton" (click)="submit()">
+              YES
+            </button>
+            <button id="noButton" (click)="dismissModal()">
+              NO
+            </button>
+          </form>
+      </div>
+    </div>
+  `,
+  pipes: [blocklyApp.TranslatePipe]
+})
+.Class({
+  constructor: [
+    blocklyApp.AudioService, blocklyApp.KeyboardInputService, blocklyApp.VariableModalService,
+    function(audioService, keyboardService, variableService) {
+      this.workspace = blocklyApp.workspace;
+      this.variableModalService = variableService;
+      this.audioService = audioService;
+      this.keyboardInputService = keyboardService
+      this.modalIsVisible = false;
+      this.activeButtonIndex = -1;
+      this.currentVariableName = "";
+      this.count = 0;
+
+      var that = this;
+      this.variableModalService.registerPreRemoveShowHook(
+        function(name, count) {
+          that.currentVariableName = name;
+          that.count = count
+          that.modalIsVisible = true;
+
+          that.keyboardInputService.setOverride({
+            // Tab key: navigates to the previous or next item in the list.
+            '9': function(evt) {
+              evt.preventDefault();
+              evt.stopPropagation();
+
+              if (evt.shiftKey) {
+                // Move to the previous item in the list.
+                if (that.activeButtonIndex <= 0) {
+                  that.activeActionButtonIndex = 0;
+                  that.audioService.playOopsSound();
+                } else {
+                  that.activeButtonIndex--;
+                }
+              } else {
+                // Move to the next item in the list.
+                if (that.activeButtonIndex == that.numInteractiveElements() - 1) {
+                  that.audioService.playOopsSound();
+                } else {
+                  that.activeButtonIndex++;
+                }
+              }
+
+              that.focusOnOption(that.activeButtonIndex);
+            },
+            // Escape key: closes the modal.
+            '27': function() {
+              that.dismissModal();
+            },
+            // Up key: no-op.
+            '38': function(evt) {
+              evt.preventDefault();
+            },
+            // Down key: no-op.
+            '40': function(evt) {
+              evt.preventDefault();
+            }
+          });
+
+          setTimeout(function() {
+            document.getElementById('label').focus();
+          }, 150);
+        }
+      );
+    }
+  ],
+  // Caches the current text variable as the user types.
+  setTextValue: function(newValue) {
+    this.variableName = newValue;
+  },
+  // Closes the modal (on both success and failure).
+  hideModal_: function() {
+    this.modalIsVisible = false;
+    this.keyboardInputService.clearOverride();
+  },
+  // Focuses on the button represented by the given index.
+  focusOnOption: function(index) {
+    var elements = this.getInteractiveElements();
+    var button = elements[index];
+    button.focus();
+  },
+  // Counts the number of interactive elements for the modal.
+  numInteractiveElements: function() {
+    var elements = this.getInteractiveElements();
+    return elements.length;
+  },
+  // Gets all the interactive elements for the modal.
+  getInteractiveElements: function() {
+    return Array.prototype.filter.call(
+      document.getElementById("varForm").elements, function(element) {
+      if (element.type === 'hidden') {
+        return false;
+      }
+      if (element.disabled) {
+        return false;
+      }
+      if (element.tabIndex < 0) {
+        return false;
+      }
+      return true;
+    });
+  },
+  // Submits the name change for the variable.
+  submit: function() {
+    blocklyApp.workspace.deleteVariableInternal_(this.currentVariableName);
+    this.hideModal_();
+  },
+  // Dismisses and closes the modal.
+  dismissModal: function() {
+    this.hideModal_();
+  }
+})
diff --git a/accessible/variable-modal.component.js b/accessible/variable-rename-modal.component.js
similarity index 92%
rename from accessible/variable-modal.component.js
rename to accessible/variable-rename-modal.component.js
index 43e882547..55d085108 100644
--- a/accessible/variable-modal.component.js
+++ b/accessible/variable-rename-modal.component.js
@@ -18,13 +18,13 @@
  */
 
 /**
- * @fileoverview Component representing the variable modal.
+ * @fileoverview Component representing the variable rename modal.
  *
  * @author corydiers@google.com (Cory Diers)
  */
 
-blocklyApp.VariableModalComponent = ng.core.Component({
-  selector: 'blockly-variable-modal',
+blocklyApp.VariableRenameModalComponent = ng.core.Component({
+  selector: 'blockly-rename-variable-modal',
   template: `
     <div *ngIf="modalIsVisible"class="blocklyModalCurtain"
          (click)="dismissModal()">
@@ -65,7 +65,7 @@ blocklyApp.VariableModalComponent = ng.core.Component({
       this.currentVariableName = "";
 
       var that = this;
-      this.variableModalService.registerPreShowHook(
+      this.variableModalService.registerPreRenameShowHook(
         function(oldName) {
           that.currentVariableName = oldName;
           that.modalIsVisible = true;
diff --git a/core/field.js b/core/field.js
index e815683b5..4114f1bae 100644
--- a/core/field.js
+++ b/core/field.js
@@ -159,6 +159,13 @@ Blockly.Field.prototype.init = function() {
   this.render_();
 };
 
+/**
+ * Initializes the model of the field after it has been installed on a block.
+ * No-op by default.
+ */
+Blockly.Field.prototype.initModel = function() {
+};
+
 /**
  * Dispose of all DOM objects belonging to this editable field.
  */
diff --git a/core/field_variable.js b/core/field_variable.js
index be8a68033..553d2a554 100644
--- a/core/field_variable.js
+++ b/core/field_variable.js
@@ -73,6 +73,12 @@ Blockly.FieldVariable.prototype.init = function() {
     return;
   }
   Blockly.FieldVariable.superClass_.init.call(this);
+
+  // TODO (1010): Change from init/initModel to initView/initModel
+  this.initModel();
+};
+
+Blockly.FieldVariable.prototype.initModel = function() {
   if (!this.getValue()) {
     // Variables without names get uniquely named for this workspace.
     var workspace =
diff --git a/core/workspace.js b/core/workspace.js
index 95dc26c00..d5c355d3f 100644
--- a/core/workspace.js
+++ b/core/workspace.js
@@ -297,7 +297,8 @@ Blockly.Workspace.prototype.getVariableUses = function(name) {
 };
 
 /**
- * Delete a variables and all of its uses from this workspace.
+ * Delete a variables and all of its uses from this workspace. May prompt the
+ * user for confirmation.
  * @param {string} name Name of variable to delete.
  */
 Blockly.Workspace.prototype.deleteVariable = function(name) {
@@ -320,14 +321,6 @@ Blockly.Workspace.prototype.deleteVariable = function(name) {
   }
 
   var workspace = this;
-  function doDeletion() {
-    Blockly.Events.setGroup(true);
-    for (var i = 0; i < uses.length; i++) {
-      uses[i].dispose(true, false);
-    }
-    Blockly.Events.setGroup(false);
-    workspace.variableList.splice(variableIndex, 1);
-  }
   if (uses.length > 1) {
     // Confirm before deleting multiple blocks.
     Blockly.confirm(
@@ -335,15 +328,31 @@ Blockly.Workspace.prototype.deleteVariable = function(name) {
         replace('%2', name),
         function(ok) {
           if (ok) {
-            doDeletion();
+            workspace.deleteVariableInternal_(name);
           }
         });
   } else {
     // No confirmation necessary for a single block.
-    doDeletion();
+    this.deleteVariableInternal_(name);
   }
 };
 
+/**
+ * Deletes a variable and all of its uses from this workspace without asking the
+ * user for confirmation.
+ * @private
+ */
+Blockly.Workspace.prototype.deleteVariableInternal_ = function(name) {
+  var uses = this.getVariableUses(name);
+  var variableIndex = this.variableIndexOf(name);
+  Blockly.Events.setGroup(true);
+  for (var i = 0; i < uses.length; i++) {
+    uses[i].dispose(true, false);
+  }
+  Blockly.Events.setGroup(false);
+  this.variableList.splice(variableIndex, 1);
+};
+
 /**
  * Check whether a variable exists with the given name.  The check is
  * case-insensitive.
diff --git a/demos/accessible/index.html b/demos/accessible/index.html
index f7eef34d8..5a60b82a4 100644
--- a/demos/accessible/index.html
+++ b/demos/accessible/index.html
@@ -32,7 +32,8 @@
   <script src="../../accessible/field-segment.component.js"></script>
   <script src="../../accessible/block-options-modal.component.js"></script>
   <script src="../../accessible/toolbox-modal.component.js"></script>
-  <script src="../../accessible/variable-modal.component.js"></script>
+  <script src="../../accessible/variable-rename-modal.component.js"></script>
+  <script src="../../accessible/variable-remove-modal.component.js"></script>
   <script src="../../accessible/sidebar.component.js"></script>
   <script src="../../accessible/workspace-block.component.js"></script>
   <script src="../../accessible/workspace.component.js"></script>