Inv(#1020): erase arbitrary child widgets

src/gui/panel/timeline-panel.cpp

@@ -78,22 +78,29 @@ namespace panel {
       twoParts_.pack_start(buttons_, Gtk::PACK_SHRINK);
       twoParts_.pack_start(frame_);
       
-      buttons_.add(button_1_);
-      buttons_.add(button_2_);
-      buttons_.add(button_3_);
       buttons_.set_layout(Gtk::BUTTONBOX_START);
       
+      // buttons to trigger experiments
       button_1_.set_label("Experiment _1");
       button_1_.signal_clicked().connect(
                   mem_fun(*this, &TimelinePanel::experiment_1));
+      buttons_.add(button_1_);
       
       button_2_.set_label("Experiment _2");
       button_2_.signal_clicked().connect(
                   mem_fun(*this, &TimelinePanel::experiment_2));
+      buttons_.add(button_2_);
       
       button_3_.set_label("Experiment _3");
       button_3_.signal_clicked().connect(
                   mem_fun(*this, &TimelinePanel::experiment_3));
+      buttons_.add(button_3_);
+      
+      button_4_.set_label("Experiment _4");
+      button_4_.signal_clicked().connect(
+                  mem_fun(*this, &TimelinePanel::experiment_4));
+      buttons_.add(button_4_);
+      //(End)buttons...
       
       frame_.add(scroller_);
       frame_.set_border_width(5);
@@ -170,6 +177,19 @@ namespace panel {
   }
   
   
+  void
+  TimelinePanel::experiment_4()
+  {
+    frame_.set_label("Experiment 4...");
+    uint killPos = rand() % childz_.size();
+    ChildV::iterator killThat(&childz_[killPos]);
+    ChildEx* victim = *killThat;
+    childz_.erase (killThat);
+    canvas_.remove (*victim);
+    delete victim;
+  }
+  
+  
   /* === Support for Investigation === */
   
   namespace {

src/gui/panel/timeline-panel.hpp

@@ -82,7 +82,7 @@ namespace panel {
    *  5. bind signals to those widgets, to verify event dispatching
    *  6. bind some further signal(s) to the ~GtkLayout container
    *  7. hide and re-show a partially and a totally overlapped widget
-   *  8. find a way to move a widget ✔
+   *  8. find a way to move a widget ✔ and delete arbitrary widgets ✔
    *  9. expand an existing widget (text change)
    *  10. build a custom "clip" widget
    *  11. retrofit all preceding tests to use this "clip" widget
@@ -108,6 +108,7 @@ namespace panel {
       Gtk::Button button_1_;
       Gtk::Button button_2_;
       Gtk::Button button_3_;
+      Gtk::Button button_4_;
       Gtk::Frame frame_;
       Gtk::ScrolledWindow scroller_;
       Gtk::Layout canvas_;
@@ -120,6 +121,7 @@ namespace panel {
       void experiment_1();
       void experiment_2();
       void experiment_3();
+      void experiment_4();
     };
   
   

wiki/renderengine.html

@@ -2635,7 +2635,7 @@ In the most general case, there can be per-track content and nested content at t
 → important question: how to [[organise the widgets|GuiTimelineWidgetStructure]]
 </pre>
 </div>
-<div title="GuiTimelineWidgetStructure" creator="Ichthyostega" modifier="Ichthyostega" created="201410250002" modified="201610290124" tags="GuiPattern discuss decision impl" changecount="44">
+<div title="GuiTimelineWidgetStructure" creator="Ichthyostega" modifier="Ichthyostega" created="201410250002" modified="201610291403" tags="GuiPattern discuss decision impl" changecount="45">
 <pre>The Timeline is probably the most prominent place in the GUI where we need to come up with a custom UI design.
 Instead of combining standard components in one of the well-known ways, here we need to come up with our own handling solution -- which also means to write one or several custom GTK widgets. Thus the question of layout and screen space division and organisation becomes a crucial design decision. The ~GTK-2 Gui, as implemented currently, did already take some steps along this route, yet this kind of decision should be cast and documented explicitly (be it after the fact).
 
@@ -2702,6 +2702,10 @@ In order to build a sensible plan for our timeline structure, we need to investi
 :children added later are always on top.
 ;moving child widgets
 :works as expected
+;delete child widgets
+:is possible by the {{{Container::remove(Widget*)}}} function
+:removed child widgets will also removed from display (hidden)
+:but the widget object needs to be deleted manually, because detached widgets are no longer managed by GTK
 ;iteration over child widgets
 :problematic
 :* the signal based {{{foreach}}} does not work -- there seems to be a problem with the slot's signature causing a wrong address to be passed in

wiki/thinkPad.ichthyo.mm

@@ -9401,6 +9401,9 @@
 <node CREATED="1477748350140" ID="ID_1672717051" MODIFIED="1477748361823" TEXT="align all in a row">
 <icon BUILTIN="button_ok"/>
 </node>
+<node CREATED="1477749635577" ID="ID_592134506" MODIFIED="1477749644284" TEXT="delete arbitrary children">
+<icon BUILTIN="button_ok"/>
+</node>
 </node>
 <node CREATED="1477595418670" ID="ID_1275908576" MODIFIED="1477596119218" TEXT="# expand an existing widget (text change)">
 <font ITALIC="true" NAME="SansSerif" SIZE="12"/>