Several changes:

 - Added touchMoved event handling to WTableView
 - WFileDropWidget fallback with file-picker
 - add method to display file-upload as another widget
 - Fixed includes in WWidgetItem
 - ImageUtils: JWt fixes

Author: RockinRoel

resources/themes/bootstrap/2/wt.css

@@ -1028,3 +1028,7 @@ body.Wt-rtl .Wt-treeview .Wt-ctrl.noexpand {
 .Wt-filedropzone-hover * {
   pointer-events: none;
 }
+
+.Wt-fileupload-hidden {
+    display: none !important;
+}

resources/themes/bootstrap/2/wt.less

@@ -1110,3 +1110,7 @@ body.Wt-rtl {
 .Wt-filedropzone-hover * {
     pointer-events: none;
 }
+
+.Wt-fileupload-hidden {
+    display: none !important;
+}

resources/themes/bootstrap/3/wt.css

@@ -1201,3 +1201,7 @@ body.Wt-rtl .Wt-treeview .Wt-ctrl.noexpand {
 .Wt-filedropzone-hover * {
   pointer-events: none;
 }
+
+.Wt-fileupload-hidden {
+    display: none !important;
+}

resources/themes/bootstrap/3/wt.less

@@ -1107,3 +1107,7 @@ body.Wt-rtl {
 .Wt-filedropzone-hover * {
     pointer-events: none;
 }
+
+.Wt-fileupload-hidden {
+    display: none !important;
+}

resources/themes/default/wt.css

@@ -1176,3 +1176,7 @@ table.x-grid3-row-table {
 .Wt-filedropzone-hover * {
     pointer-events: none;
 }
+
+.Wt-fileupload-hidden {
+    display: none !important;
+}

resources/themes/polished/wt.css

@@ -1219,3 +1219,7 @@ table.x-grid3-row-table {
 .Wt-filedropzone-hover * {
     pointer-events: none;
 }
+
+.Wt-fileupload-hidden {
+    display: none !important;
+}

src/Wt/WAbstractItemView.C

@@ -1421,6 +1421,12 @@ void WAbstractItemView::handleTouchStart(const std::vector<WModelIndex>& indices
   touchStarted_.emit(indices, event);
 }
 
+void WAbstractItemView::handleTouchMove(const std::vector<WModelIndex>& indices,
+                                        const WTouchEvent& event)
+{
+  touchMoved_.emit(indices, event);
+}
+
 void WAbstractItemView::handleTouchEnd(const std::vector<WModelIndex>& indices,
 				       const WTouchEvent& event)
 {

src/Wt/WAbstractItemView.h

@@ -727,6 +727,14 @@ class WT_API WAbstractItemView : public WCompositeWidget
    */
   Signal<std::vector<WModelIndex>, WTouchEvent>& touchStarted() { return touchStarted_; }
 
+  /*! \brief %Signal emitted when one or more fingers are moved on the screen.
+   *
+   * When the event happened over an item, the first argument
+   * indicates the items that were touched. The indices in the model index
+   * vector match the indices in the \link WTouchEvent::changedTouches() changedTouches() of the WTouchEvent\endlink.
+   */
+  Signal<std::vector<WModelIndex>, WTouchEvent>& touchMoved() { return touchMoved_; }
+
   /*! \brief %Signal emitted when one or more fingers are removed from the screen.
    *
    * When the event happened over an item, the first argument
@@ -1038,6 +1046,11 @@ class WT_API WAbstractItemView : public WCompositeWidget
   virtual void handleTouchStart(const std::vector<WModelIndex>& indices,
 				const WTouchEvent& event);
 
+  /*! \brief Handles a touch moved event.
+   */
+  virtual void handleTouchMove(const std::vector<WModelIndex>& indices,
+                               const WTouchEvent& event);
+
   /*! \brief Handles a touch ended event.
    */
   virtual void handleTouchEnd(const std::vector<WModelIndex>& indices,
@@ -1114,6 +1127,7 @@ class WT_API WAbstractItemView : public WCompositeWidget
   Signal<WModelIndex, WMouseEvent> mouseWentUp_;
   Signal<WModelIndex, WTouchEvent> touchStart_;
   Signal<std::vector<WModelIndex>, WTouchEvent> touchStarted_;
+  Signal<std::vector<WModelIndex>, WTouchEvent> touchMoved_;
   Signal<std::vector<WModelIndex>, WTouchEvent> touchEnded_;
   Signal<> selectionChanged_;
   Signal<> pageChanged_;

src/Wt/WFileUpload.C

@@ -243,6 +243,22 @@ void WFileUpload::setProgressBar(std::unique_ptr<WProgressBar> bar)
   }
 }
 
+void WFileUpload::setDisplayWidget(WInteractWidget *widget) {
+  addStyleClass("Wt-fileupload-hidden");
+  widget->clicked().connect(displayWidgetClickJS());
+}
+  
+std::string WFileUpload::displayWidgetClickJS() {
+  return "function(obj, event) {" +
+       jsRef() + ".click();" +
+    "  var children = " + jsRef() + ".children;" +
+    "  for (var i=0; i < children.length; i++) {" +
+    "    children[i].click();" +
+    "  }" +
+    "}";
+}
+
+
 EventSignal<>& WFileUpload::uploaded()
 {
   return *voidEventSignal(UPLOADED_SIGNAL, true);

src/Wt/WFileUpload.h

@@ -192,6 +192,17 @@ class WT_API WFileUpload : public WWebWidget
    */
   bool canUpload() const { return fileUploadTarget_ != nullptr; }
 
+  /*! \brief Use the click signal of another widget to open the file picker.
+   *
+   * This hides the default WFileUpload widget and uses the click-signal of the argument to
+   * open the file picker. The upload logic is still handled by WFileUpload behind the scenes.
+   * This action cannot be undone.
+   * 
+   * WFileUpload does not take ownership of the widget, nor does it display it. You must still 
+   * place it in the widget tree yourself.
+   */
+  void setDisplayWidget(WInteractWidget *widget);
+  
   /*! \brief %Signal emitted when a new file was uploaded.
    *
    * This signal is emitted when file upload has been completed.  It
@@ -339,6 +350,8 @@ class WT_API WFileUpload : public WWebWidget
   void onData(::uint64_t current, ::uint64_t total);
   void onDataExceeded(::uint64_t dataExceeded);
 
+  std::string displayWidgetClickJS();
+
   virtual void setRequestTooLarge(::int64_t size) override;
 
 protected: