From 778e1de1665a46925a776aba3d86a3c73a9b0d72 Mon Sep 17 00:00:00 2001
From: Jelle Kralt <jelle@jellekralt.nl>
Date: Fri, 31 Jul 2015 14:33:13 +0200
Subject: [PATCH] Better events and text selection

Added better event handling, directive destroying and custom text
selection
---
 src/ng-drag-scroll.js | 110 +++++++++++++++++++++++++++++++++++-------
 1 file changed, 93 insertions(+), 17 deletions(-)

diff --git a/src/ng-drag-scroll.js b/src/ng-drag-scroll.js
index 34c5ce3..ad6e92c 100644
--- a/src/ng-drag-scroll.js
+++ b/src/ng-drag-scroll.js
@@ -5,52 +5,95 @@
         .module('dragscroll')
         .directive('dragScroll', DragScroll);
 
-    DragScroll.$inject = ['$document', '$window'];
+    DragScroll.$inject = ['$document', '$window', '$parse'];
 
     /* @ngInject */
-    function DragScroll($document, $window) {
+    function DragScroll($document, $window, $parse) {
         //Usage:
         //<div drag-scroll>Lorem ipsum dolor sit amet</div>
         var directive = {
             scope: false,
             restrict: 'A',
             link: function($scope, $element, $attributes, vm) {
-                var pushed = 0;
+                var allowedClickOffset = 5;
+                var pushed = false;
+                var onDragStart = $parse($attributes.onDragStart);
+                var onDragEnd = $parse($attributes.onDragEnd);
                 var axis = $attributes.axis || false;
+                var startClientX;
+                var startClientY;
                 var lastClientX;
                 var lastClientY;
 
                 // Set event listeners
                 $element.on('mousedown', handleMouseDown);
-                angular.element($window).on('mouseup', handleMouseUp);
-                angular.element($window).on('mousemove', handleMouseMove);
 
-                // Handle destroy event
+                // Set destroy listener
                 $scope.$on('$destroy', destroy);
 
+                /**
+                 * Sets the event listeners for the mouseup and mousedown events
+                 */
+                function setDragListeners () {
+                    angular.element($window).on('mouseup', handleMouseUp);
+                    angular.element($window).on('mousemove', handleMouseMove);
+                }
+
+                /**
+                 * Removes the event listeners for the mouseup and mousedown events
+                 */
+                function removeDragListeners () {
+                    angular.element($window).off('mouseup', handleMouseUp);
+                    angular.element($window).off('mousemove', handleMouseMove);
+                }
+
                 /**
                  * Handles mousedown event
                  * @param {object} e MouseDown event
                  */
                 function handleMouseDown (e) {
-                    var dragAllowed = !('prevent-drag' in e.target.attributes);
 
-                    if(dragAllowed) {
-                        pushed = 1;
-                        lastClientX = e.clientX;
-                        lastClientY = e.clientY;
+                    $scope.$apply(function() {
+                        onDragStart($scope);
+                    });
 
-                        //e.preventDefault();
-                        e.stopPropagation();
-                    }
+                    // Set mouse drag listeners
+                    setDragListeners();
+
+                    // Set 'pushed' state
+                    pushed = true;
+                    lastClientX = startClientX = e.clientX;
+                    lastClientY = startClientY = e.clientY;
+
+                    clearSelection();
+
+                    e.preventDefault();
+                    e.stopPropagation();
                 }
 
                 /**
                  * Handles mouseup event
                  * @param {object} e MouseUp event
                  */
-                function handleMouseUp () {
-                    pushed = 0;
+                function handleMouseUp (e) {
+                    var selectable = ('drag-scroll-text' in e.target.attributes);
+                    var withinXConstraints = (e.clientX >= (startClientX - allowedClickOffset) && e.clientX <= (startClientX + allowedClickOffset));
+                    var withinYConstraints = (e.clientY >= (startClientY - allowedClickOffset) && e.clientY <= (startClientY + allowedClickOffset));
+
+                    // Set 'pushed' state
+                    pushed = false;
+
+                    // Check if cursor falls within X and Y axis constraints
+                    if(selectable && withinXConstraints && withinYConstraints) {
+                        // If so, select the text inside the target element
+                        selectText(e.target);
+                    }
+
+                    $scope.$apply(function() {
+                        onDragEnd($scope);
+                    });
+
+                    removeDragListeners();
                 }
 
                 /**
@@ -58,7 +101,6 @@
                  * @param {object} e MouseMove event
                  */
                 function handleMouseMove (e) {
-
                     if (pushed) {
                         if(!axis || axis === 'x') {
                             $element[0].scrollLeft -= (-lastClientX + (lastClientX = e.clientX));
@@ -68,6 +110,7 @@
                         }
                     }
 
+                    e.preventDefault();
                 }
 
                 /**
@@ -79,9 +122,42 @@
                     angular.element($window).off('mousemove', handleMouseMove);
                 }
 
+                /**
+                 * Selects text for a specific element
+                 * @param {object} element Selected element
+                 */
+                function selectText (element) {
+                    if ($window.document.selection) {
+                        var range = $window.document.body.createTextRange();
+                        range.moveToElementText(element);
+                        range.select();
+                    } else if ($window.getSelection) {
+                        var range = $window.document.createRange();
+                        range.selectNode(element);
+                        $window.getSelection().addRange(range);
+                    }
+                }
+
+                /**
+                 * Clears text selection
+                 */
+                function clearSelection () {
+                    if ($window.getSelection) {
+                        if ($window.getSelection().empty) {  // Chrome
+                            $window.getSelection().empty();
+                        } else if ($window.getSelection().removeAllRanges) {  // Firefox
+                            $window.getSelection().removeAllRanges();
+                        }
+                    } else if ($document.selection) {  // IE?
+                        $document.selection.empty();
+                    }
+                }
+
+
             }
         };
         return directive;
+
     }
 
 })();