X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/dep-ui/blobdiff_plain/ac26861cd2097171f4f61adf7277af93c7094b16..aca28a1d25ea50c837b2699964ef3c53f449f0c1:/dep-ui.js

diff --git a/dep-ui.js b/dep-ui.js
index 29f5d6b..6803915 100644
--- a/dep-ui.js
+++ b/dep-ui.js
@@ -18,36 +18,57 @@
  * GNU Library General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ * along with this program; if not, see <https://www.gnu.org/licenses/>.
  */
 
-var DEP_UI = {}; (function () { with (DEP_UI) {
+var DEP_UI = {}; (function () {
 
 /*----- Utility functions and classes -------------------------------------*/
 
-DEP_UI.elt = function (id) {
+function debug(msg) {
+  /* Write the string MSG to the `trace' element, if there is one. */
+
+  var e = elt('trace');
+  if (e !== null) e.textContent += msg;
+}
+DEP_UI.debug = debug;
+
+function trap(what, func) {
+  try {
+    func();
+  } catch (e) {
+    debug('caught exception in ' + what + ': ' + e);
+    throw e;
+  }
+}
+DEP_UI.trap = trap;
+
+function elt(id) {
   /* Find and return the element with the given ID. */
   return document.getElementById(id);
 }
+DEP_UI.elt = elt;
 
-DEP_UI.add_elt_class = function (elt, cls) {
+function add_elt_class(elt, cls) {
   /* Add the class name CLS to element ELT's `class' attribute. */
 
   if (!elt.className.match('\\b' + cls + '\\b'))
     elt.className += ' ' + cls
 }
+DEP_UI.add_elt_class = add_elt_class;
 
-DEP_UI.rm_elt_class = function (elt, cls) {
+function rm_elt_class(elt, cls) {
   /* Remove the class name CLS from element ELT's `class' attribute. */
 
   elt.className = elt.className.replace(
     new RegExp ('\\s*\\b' + cls + '\\b\\s*'), ' ');
 }
+DEP_UI.rm_elt_class = rm_elt_class;
 
 /* A gadget which can arrange to perform an idempotent action (the FUNC
  * argument) again `soon'.
  */
-DEP_UI.Soon = function (func) {
+function Soon(func) {
   this.timer = null;
   this.func = func;
 }
@@ -63,15 +84,16 @@ Soon.prototype = {
     this.timer = setTimeout(function () { me.func(); }, 50);
   }
 };
+DEP.Soon = Soon;
 
 /*----- Conversion machinery ----------------------------------------------*/
 
 /* An exception, thrown if a conversion function doesn't like what it
  * sees.
  */
-DEP_UI.BadValue = new DEP.Tag('BadValue');
+BadValue = new DEP.Tag('BadValue'); DEP.BadValue = BadValue;
 
-DEP_UI.convert_to_numeric = function (string) {
+function convert_to_numeric(string) {
   /* Convert the argument STRING to a number. */
 
   if (!string.match('\\S')) throw BadValue;
@@ -79,26 +101,47 @@ DEP_UI.convert_to_numeric = function (string) {
   if (n !== n) throw BadValue;
   return n;
 }
+DEP_UI.convert_to_numeric = convert_to_numeric;
 
-DEP_UI.convert_from_numeric = function (num) {
+function convert_from_numeric(num) {
   /* Convert the argument number NUM to a string, in a useful way. */
   return num.toFixed(3);
 }
+DEP_UI.convert_from_numeric = convert_from_numeric;
 
 /*----- User interface functions ------------------------------------------*/
 
 /* A list of input fields which might need periodic kicking. */
 var KICK_INPUT_FIELDS = [];
 
-DEP_UI.input_field = function (id, dep, convert) {
-  /* Bind an input field (with the given ID) to a DEP, converting the user's
-   * input with the CONVERT function.
+function input_widget(id, dep, kickfn) {
+  /* Bind an input widget (with the given ID) to a DEP, calling KICKFN (with
+   * the widget element as its argument) to update DEP from the state of the
+   * widget.  This is common machinery for `input_field' and `input_radio'.
    */
 
   var e = elt(id);
 
-  function kick() {
-    /* Update the dep from the element content.  If the convert function
+  // Name the dep after our id.
+  dep.name = id;
+
+  // Arrange to update the dep `shortly after' updates.
+  function kick() { kickfn(e); }
+  var soon = new Soon(kick);
+  function kick_soon() { soon.kick(); }
+  e.addEventListener('input', kick_soon, false);
+
+  // Set our field to the correct state when the page finishes loading.
+  KICK_INPUT_FIELDS.push(kick);
+}
+
+function input_field(id, dep, convert) {
+  /* Bind an input field (with the given ID) to a DEP, converting the user's
+   * input with the CONVERT function.
+   */
+
+  input_widget(id, dep, function (e) {
+    /* Update the dep from the element content.  If the CONVERT function
      * doesn't like the input then mark the dep as bad and highlight the
      * input element.
      */
@@ -115,53 +158,24 @@ DEP_UI.input_field = function (id, dep, convert) {
       dep.make_bad();
       add_elt_class(e, 'bad');
     }
-  }
-
-  // Name the dep after our id.
-  dep.name = id;
-
-  // Arrange to update the dep `shortly after' updates.
-  var soon = new Soon(kick);
-  function kick_soon () { soon.kick(); }
-  e.addEventListener('click', kick_soon);
-  e.addEventListener('blur', kick_soon);
-  e.addEventListener('keypress', kick_soon);
-
-  // Sadly, the collection of events above isn't comprehensive, because we
-  // don't actually get told about edits as a result of clipboard operations,
-  // or even (sometimes) deletes, so add our `kick' function to a list of
-  // such functions to be run periodically just in case.
-  KICK_INPUT_FIELDS.push(kick);
+  });
 }
+DEP_UI.input_field = input_field;
 
-DEP_UI.input_radio = function (id, dep) {
+function input_radio(id, dep) {
   /* Bind a radio button (with the given ID) to a DEP.  When the user frobs
    * the button, set the dep to the element's `value' attribute.
    */
 
-  var e = elt(id);
-
-  function kick () {
-    // Make sure we're actually chosen.  We get called periodically
-    // regardless of user input.
+  input_widget(id, dep, function (e) {
+    // Make sure we're actually chosen.  We might get called regardless of
+    // user input.
     if (e.checked) dep.set_value(e.value);
-  };
-
-  // Name the dep after our id.
-  dep.name = id;
-
-  // Arrange to update the dep `shortly after' updates.
-  var soon = new Soon(kick);
-  function kick_soon () { soon.kick(); }
-  e.addEventListener('click', kick_soon);
-  e.addEventListener('changed', kick_soon);
-
-  // The situation for radio buttons doesn't seem as bad as for text widgets,
-  // but let's be on the safe side.
-  KICK_INPUT_FIELDS.push(kick);
+  });
 }
+DEP_UI.input_radio = input_radio;
 
-DEP_UI.output_field = function (id, dep, convert) {
+function output_field(id, dep, convert) {
   /* Bind a DEP to an output element (given by ID), converting the dep's
    * value using the CONVERT function.
    */
@@ -186,6 +200,7 @@ DEP_UI.output_field = function (id, dep, convert) {
   dep.add_listener(kicked);
   kicked();
 }
+DEP_UI.output_field = output_field;
 
 /*----- Periodic maintenance ----------------------------------------------*/
 
@@ -196,11 +211,8 @@ function kick_all() {
   DEP.dolist(KICK_INPUT_FIELDS, function (func) { func(); });
 }
 
-// Update the input fields relatively frequently.
-setInterval(kick_all, 500);
-
 // And make sure we get everything started when the page is fully loaded.
-window.addEventListener('load', kick_all);
+window.addEventListener('load', kick_all, false);
 
 /*----- That's all, folks -------------------------------------------------*/
-} })();
+})();