Several changes:

 - various flexlayout fixes and improvements
 - Fixed case error, fix not showing tooltip when moving off of another tooltip

examples/widgetgallery/WidgetGallery.C

@@ -60,7 +60,6 @@ WidgetGallery::WidgetGallery()
    * Add it all inside a layout
    */
   auto layout = this->setLayout(Wt::cpp14::make_unique<Wt::WVBoxLayout>());
-  layout->setPreferredImplementation(Wt::LayoutImplementation::JavaScript);
   layout->addWidget(std::move(navigation), 0);
   layout->addWidget(std::move(contentsStack), 1);
   layout->setContentsMargins(0, 0, 0, 0);
@@ -77,20 +76,17 @@ Wt::WMenuItem *WidgetGallery::addToMenu(Wt::WMenu *menu,
   auto pane_ = pane.get();
 
   auto vLayout = result->setLayout(Wt::cpp14::make_unique<Wt::WVBoxLayout>());
-  vLayout->setPreferredImplementation(Wt::LayoutImplementation::JavaScript);
   vLayout->setContentsMargins(0, 0, 0, 0);
   vLayout->addWidget(std::move(topic));
   vLayout->addWidget(std::move(pane), 1);
 
   auto hLayout = pane_->setLayout(Wt::cpp14::make_unique<Wt::WHBoxLayout>());
-  hLayout->setPreferredImplementation(Wt::LayoutImplementation::JavaScript);
 
   auto item = Wt::cpp14::make_unique<Wt::WMenuItem>(name, std::move(result));
   auto item_ = menu->addItem(std::move(item));
 
   auto subStack = Wt::cpp14::make_unique<Wt::WStackedWidget>();
   subStack->addStyleClass("contents");
-  subStack->setOverflow(Wt::Overflow::Auto);
 
   /*
   WAnimation animation(AnimationEffect::Fade,

examples/widgetgallery/docroot/style/everywidget.css

@@ -121,7 +121,7 @@ span.reactive {
 }
 
 div.contents {
-    padding: 0px 12px 6px;
+    padding: 0px 0px 3px 12px;
 }
 
 .example-table {

examples/widgetgallery/main.C

@@ -63,7 +63,6 @@ std::unique_ptr<WApplication> createApplication(const Wt::WEnvironment& env)
 
   auto layout =
       app->root()->setLayout(cpp14::make_unique<WHBoxLayout>());
-  layout->setPreferredImplementation(Wt::LayoutImplementation::JavaScript);
   layout->setContentsMargins(0, 0, 0, 0);
   layout->addWidget(cpp14::make_unique<WidgetGallery>());
 

src/Wt/WPanel.C

@@ -41,9 +41,9 @@ WPanel::WPanel()
 
   setJavaScriptMember
     (WT_RESIZE_JS,
-     "function(self, w, h, l) {"
-     """var defined = h >= 0;"
-     """if (defined) {"
+     "function(self, w, h, s) {"
+     """var hdefined = h >= 0;"
+     """if (hdefined) {"
      ""  "var mh = " WT_CLASS ".px(self, 'maxHeight');"
      ""  "if (mh > 0) h = Math.min(h, mh);"
      """}"
@@ -56,23 +56,23 @@ WPanel::WPanel()
      """if (t)"
      ""  "h -= t.offsetHeight;"
      """h -= 8;" // padding
-     """if (defined && h > 0) {"
-     ""  "c.lh = l;"
+     """if (hdefined && h > 0) {"
+     ""  "c.lh = true;"
      ""  "c.style.height = h + 'px';"
      // this seems golden, but, JQuery docs say it doesn't work when
      // the panel is indirectly hidden: will this back-fire ?
      ""  "$(c).children().each(function() { "
      ""      "var self = $(this), "
      ""          "padding = self.outerHeight() - self.height();"
      ""      "self.height(h - padding);"
-     ""      "this.lh = l;"
+     ""      "this.lh = true;"
      ""  "});"
      """} else {"
-     ""  "c.lh = false;"
      ""  "c.style.height = '';"
+     ""  "c.lh = false;"
      ""  "$(c).children().each(function() { "
-     ""      "this.style.height = '';"
-     ""      "this.lh = false;"
+     ""    "this.style.height = '';"
+     ""    "this.lh = false;"
      ""  "});"
      """}"
      "};");

src/Wt/WStackedWidget.C

@@ -21,6 +21,7 @@ WStackedWidget::WStackedWidget()
     javaScriptDefined_(false),
     loadAnimateJS_(false)
 {
+  setOverflow(Overflow::Hidden);
   addStyleClass("Wt-stack");
 }
 

src/Wt/WTextEdit.C

@@ -52,8 +52,8 @@ void WTextEdit::init()
 
   setJavaScriptMember
     (WT_RESIZE_JS,
-     "function(e, w, h) { var obj = $('#" + id() + "').data('obj'); "
-     "obj.wtResize(e, w, h); };");
+     "function(e, w, h, s) { var obj = $('#" + id() + "').data('obj'); "
+     "obj.wtResize(e, w, h, s); };");
 
   std::string direction 
     = app->layoutDirection() == LayoutDirection::LeftToRight ? "ltr" : "rtl";

src/Wt/WTreeView.C

@@ -1062,8 +1062,8 @@ void WTreeView::defineJavaScript()
 		      + "');");
 
   setJavaScriptMember(WT_RESIZE_JS,
-		      "function(self,w,h) {"
-		      "$(self).data('obj').wtResize();"
+		      "function(self,w,h,s) {"
+		      """$(self).data('obj').wtResize();"
 		      "}");
 }
 

src/js/FlexLayoutImpl.js

@@ -11,6 +11,26 @@ WT_DECLARE_WT_MEMBER
  function(APP, id) {
    var WT = APP.WT;
 
+   function init() {
+     var el = WT.getElement(id);
+     if (!el) return;
+
+     var children = el.childNodes;
+     for (var i = 0; i < children.length; ++i) {
+       var c = children[i];
+       if (c.style.display == 'none' || 
+	   $(c).hasClass('out') ||
+	   c.className == 'resize-sensor')
+	 continue;
+
+       var of = WT.css(c, 'overflow');
+       if (of === 'visible' || of === '')
+	 c.style.overflow = 'hidden';
+     }
+   }
+
+   setTimeout(init, 0);
+
    this.adjust = function(spacing) {
      setTimeout(function() {
        var el = WT.getElement(id);
@@ -36,11 +56,16 @@ WT_DECLARE_WT_MEMBER
 
        for (var i = 0; i < children.length; ++i) {
 	 var c = children[i];
+
 	 if (c.style.display == 'none' || 
 	     $(c).hasClass('out') ||
 	     c.className == 'resize-sensor')
 	   continue;
 
+	 /* Re-trigger resize-sensor */
+	 if (c.resizeSensor)
+	   c.resizeSensor.trigger();
+
 	 var stretch;
 
 	 if (totalStretch === 0)

src/js/ResizeSensor.js

@@ -77,15 +77,19 @@ function(WT, element) {
         shrink.scrollTop = 100000;
     };
 
+    element.resizeSensor.trigger = function() {
+      if (element.wtResize)
+	element.wtResize(element, lastWidth, lastHeight, false);
+    };
+
     reset();
     var dirty = false;
     var lastWidth, lastHeight;
 
     var dirtyChecking = function() {
         if (dirty) {
-	    if (element.wtResize)
-		element.wtResize(element, lastWidth, lastHeight);
-            dirty = false;
+	  element.resizeSensor.trigger();
+	  dirty = false;
         }
 
         requestAnimationFrame(dirtyChecking);

src/js/WCartesianChart.js

@@ -11,6 +11,7 @@ WT_DECLARE_WT_MEMBER_BIG
   // target: the WPaintedWidget JavaScript obj, with:
   //   repaint
   //   canvas
+  //   combinedTransform is set by WCartesianChart
   // config: the initial configuration (can be overridden with updateConfig)
   //   curveManipulation (determines whether series manipulation is enabled)
   //   seriesSelection (determines whether series selection is enabled)
@@ -375,7 +376,7 @@ WT_DECLARE_WT_MEMBER_BIG
       }
       if (tobj.tooltipOuterDiv) {
         document.body.removeChild(tobj.tooltipOuterDiv);
-        tobj.tooltipEl = null;
+        tobj.toolTipEl = null;
         tobj.tooltipOuterDiv = null;
       }
     }
@@ -638,6 +639,8 @@ WT_DECLARE_WT_MEMBER_BIG
     }
 
     function loadTooltip() {
+      if (tobj.toolTipEl)
+        return;
       APP.emit(target.widget, "loadTooltip", tobj.tooltipPosition[X], tobj.tooltipPosition[Y]);
     }
 
@@ -684,7 +687,7 @@ WT_DECLARE_WT_MEMBER_BIG
         var c = WT.widgetCoordinates(target.canvas, event);
         if (!isPointInRect(c, configArea())) return;
 
-        if (!tobj.tooltipEl && hasToolTips()) {
+        if (hasToolTips()) {
           tobj.tooltipPosition = [c.x,c.y];
           tobj.tooltipTimeout = setTimeout(function() {
             loadTooltip();