From b9ae53f86b73ec13f7003f006679d5924ab1af22 Mon Sep 17 00:00:00 2001
From: Damyon Wiese <damyon@moodle.com>
Date: Fri, 8 Sep 2017 14:51:31 +0800
Subject: [PATCH] MDL-59758 js: auto_rows module easier to use

Allow passing the direct text area, or a container.
Trigger change events on the text area, not the container.
Properly handle starting with rows > 1
---
 lib/amd/build/auto_rows.min.js |  2 +-
 lib/amd/src/auto_rows.js       | 43 +++++++++++++++++++++++++---------
 2 files changed, 33 insertions(+), 12 deletions(-)

diff --git a/lib/amd/build/auto_rows.min.js b/lib/amd/build/auto_rows.min.js
index 30ec60f6a8251..c95209bc9f0be 100644
--- a/lib/amd/build/auto_rows.min.js
+++ b/lib/amd/build/auto_rows.min.js
@@ -1 +1 @@
-define(["jquery"],function(a){var b={ELEMENT:"[data-auto-rows]"},c={ROW_CHANGE:"autorows:rowchange"},d=function(a){var b=a.attr("rows"),c=a.attr("data-max-rows"),d=a.height(),e=a.innerHeight(),f=e-d;a.height("1px");var g=a[0].scrollHeight,h=(g-f)/(d/b);return a.css("height",""),c&&h>=c?c:h},e=function(e){a(e).on("input propertychange",b.ELEMENT,function(b){var f=a(b.target),g=f.attr("rows"),h=d(f);h!=g&&(f.attr("rows",h),a(e).trigger(c.ROW_CHANGE))})};return{init:e,events:c}});
\ No newline at end of file
+define(["jquery"],function(a){var b={ELEMENT:"[data-auto-rows]"},c={ROW_CHANGE:"autorows:rowchange"},d=function(a){var b=a.attr("rows"),c=a.data("min-rows"),d=a.attr("data-max-rows"),e=a.height(),f=a.innerHeight(),g=f-e;a.height("1px");var h=a[0].scrollHeight,i=(h-g)/(e/b);return a.css("height",""),i<c?c:d&&i>=d?d:i},e=function(b,e){var f=a(e.target),g=f.data("min-rows"),h=f.attr("rows");"undefined"==typeof g&&f.data("min-rows",h);var i=d(f);i!=h&&(f.attr("rows",i),f.trigger(c.ROW_CHANGE))},f=function(c){a(c).data("auto-rows")?a(c).on("input propertychange",e.bind(this,c)):a(c).on("input propertychange",b.ELEMENT,e.bind(this,c))};return{init:f,events:c}});
\ No newline at end of file
diff --git a/lib/amd/src/auto_rows.js b/lib/amd/src/auto_rows.js
index 1532ad2d7915a..2c04a47fed9b4 100644
--- a/lib/amd/src/auto_rows.js
+++ b/lib/amd/src/auto_rows.js
@@ -42,6 +42,7 @@ define(['jquery'], function($) {
      */
     var calculateRows = function(element) {
         var currentRows = element.attr('rows');
+        var minRows = element.data('min-rows');
         var maxRows = element.attr('data-max-rows');
 
         var height = element.height();
@@ -58,13 +59,38 @@ define(['jquery'], function($) {
         // based on the row attribute.
         element.css('height', '');
 
-        if (maxRows && rows >= maxRows) {
+        if (rows < minRows) {
+            return minRows;
+        } else if (maxRows && rows >= maxRows) {
             return maxRows;
         } else {
             return rows;
         }
     };
 
+    /**
+     * Listener for change events to trigger resizing of the element.
+     *
+     * @method changeListener
+     * @param {Event} e The triggered event.
+     * @private
+     */
+    var changeListener = function(root, e) {
+        var element = $(e.target);
+        var minRows = element.data('min-rows');
+        var currentRows = element.attr('rows');
+
+        if (typeof minRows === "undefined") {
+            element.data('min-rows', currentRows);
+        }
+        var rows = calculateRows(element);
+
+        if (rows != currentRows) {
+            element.attr('rows', rows);
+            element.trigger(EVENTS.ROW_CHANGE);
+        }
+    };
+
     /**
      * Add the event listeners for all text areas within the given element.
      *
@@ -73,16 +99,11 @@ define(['jquery'], function($) {
      * @public
      */
     var init = function(root) {
-        $(root).on('input propertychange', SELECTORS.ELEMENT, function(e) {
-            var element = $(e.target);
-            var currentRows = element.attr('rows');
-            var rows = calculateRows(element);
-
-            if (rows != currentRows) {
-                element.attr('rows', rows);
-                $(root).trigger(EVENTS.ROW_CHANGE);
-            }
-        });
+        if ($(root).data('auto-rows')) {
+            $(root).on('input propertychange', changeListener.bind(this, root));
+        } else {
+            $(root).on('input propertychange', SELECTORS.ELEMENT, changeListener.bind(this, root));
+        }
     };
 
     return /** @module core/auto_rows */ {