gui: Add support for multiple stacked modals

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3288

gui/default/syncthing/core/modalDirective.js

@@ -11,6 +11,63 @@ angular.module('syncthing.core')
                 icon: '@',
                 close: '@',
                 large: '@'
+            },
+            link: function (scope, element, attrs, tabsCtrl) {
+
+                // before modal show animation
+                $(element).on('show.bs.modal', function () {
+
+                    // cycle through open modals, acertain modal with highest z-index
+                    var largestZ = 1040;
+                    $('.modal:visible').each(function (i) {
+                        var thisZ = parseInt($(this).css('zIndex'));
+                        if (thisZ > largestZ) {
+                            largestZ = thisZ;
+                        }
+                    });
+
+                    // set this modal's z-index to be 10 above the highest z
+                    var aboveLargestZ = largestZ + 10;
+                    $(element).css('zIndex', aboveLargestZ);
+
+                    // set backdrop z-index. timeout used because element does not exist immediatly
+                    setTimeout(function () {
+                        $('.modal-backdrop:not(:last)').removeClass('in').addClass('out');
+                        $('.modal-backdrop:last').attr('for-modal-id', $(element).attr('id')).css('zIndex', aboveLargestZ - 5);
+                    }, 0);
+
+                });
+
+                // BEFORE modal hide animation
+                $(element).on('hide.bs.modal', function () {
+
+                    // find and unhide the next backdrop down in z order
+                    var sel = false, largestZ = 0;
+                    $('.modal-backdrop').each(function (i) {
+                        console.log('sel each');
+                        var thisZ = parseInt($(this).css('zIndex'));
+                        if (thisZ > largestZ && $(this).attr('for-modal-id') !== $(element).attr('id')) {
+                            largestZ = thisZ;
+                            sel = i;
+                        }
+                    });
+                    if (sel !== false) {
+                        $('.modal-backdrop:eq(' + sel + ')').removeClass('out').addClass('in');
+                    }
+                });
+
+                // AFTER modal hide animation
+                $(element).on('hidden.bs.modal', function () {
+
+                    // reset z-index of modal to normal
+                    $(element).css('zIndex', 1040);
+
+                    // fix scrolling by re-adding .modal-open to body
+                    if ($('.modal:visible').length > 0) {
+                        $('body').addClass('modal-open');
+                    }
+
+                });
             }
         };
     });