setting to change timeline zoom

data/pref.xml

@@ -257,6 +257,7 @@
       <option id="color2" type="app::Color" default="app::Color::fromRgb(192, 192, 192)" migrate="Option.CheckedBgColor2" />
     </section>
     <section id="thumbnails">
+      <option id="zoom" type="double" default="1" />
       <option id="enabled" type="bool" default="false" />
       <option id="overlay_enabled" type="bool" default="false" />
       <option id="overlay_size" type="int" default="5" />

data/widgets/timeline_conf.xml

@@ -4,6 +4,9 @@
 <vbox id="timeline_conf">
   <separator cell_hspan="2" text="Thumbnails:" left="true" horizontal="true" />
   <grid columns="3">
+    <label text="Zoom:" />
+    <slider min="10" max="100" id="zoom" cell_align="horizontal" width="128" cell_hspan="2" />
+
     <check id="thumb_enabled" text="Enabled" />
     <label text="Opacity:" />
     <slider min="0" max="255" id="thumb_opacity" cell_align="horizontal" width="128" />

src/app/ui/configure_timeline_popup.cpp

@@ -62,6 +62,7 @@ ConfigureTimelinePopup::ConfigureTimelinePopup()
   m_box->behind()->Click.connect(base::Bind<void>(&ConfigureTimelinePopup::onPositionChange, this));
   m_box->infront()->Click.connect(base::Bind<void>(&ConfigureTimelinePopup::onPositionChange, this));
 
+  m_box->zoom()->Change.connect(base::Bind<void>(&ConfigureTimelinePopup::onZoomChange, this));
   m_box->thumbOpacity()->Change.connect(base::Bind<void>(&ConfigureTimelinePopup::onThumbOpacityChange, this));
   m_box->thumbBackground()->Change.connect(&ConfigureTimelinePopup::onThumbBackgroundChange, this);
   m_box->thumbEnabled()->Click.connect(base::Bind<void>(&ConfigureTimelinePopup::onThumbEnabledChange, this));
@@ -133,6 +134,7 @@ void ConfigureTimelinePopup::updateWidgetsFromCurrentSettings()
       break;
   }
 
+  m_box->zoom()->setValue(docPref.thumbnails.zoom() * 10.0);
   m_box->thumbOpacity()->setValue(docPref.thumbnails.opacity());
   m_box->thumbBackground()->setColor(docPref.thumbnails.background());
   m_box->thumbEnabled()->setSelected(docPref.thumbnails.enabled());
@@ -209,6 +211,11 @@ void ConfigureTimelinePopup::onPositionChange()
                                render::OnionskinPosition::INFRONT);
 }
 
+void ConfigureTimelinePopup::onZoomChange()
+{
+  docPref().thumbnails.zoom(m_box->zoom()->getValue()/10.0);
+}
+
 void ConfigureTimelinePopup::onThumbOpacityChange()
 {
   docPref().thumbnails.opacity(m_box->thumbOpacity()->getValue());

src/app/ui/configure_timeline_popup.h

@@ -41,6 +41,7 @@ namespace app {
     void onCurrentLayerChange();
     void onPositionChange();
 
+    void onZoomChange();
     void onThumbOpacityChange();
     void onThumbQualityChange();
     void onThumbBackgroundChange(const app::Color& color);

src/app/ui/timeline.cpp

@@ -150,8 +150,14 @@ Timeline::~Timeline()
   delete m_confPopup;
 }
 
+void Timeline::setZoom(double zoom)
+{
+  m_zoom = MID(1.0, zoom, 10.0);
+}
+
 void Timeline::onThumbnailsPrefChange()
 {
+  setZoom(docPref().thumbnails.zoom());
   invalidate();
 }
 
@@ -187,6 +193,8 @@ void Timeline::updateUsingEditor(Editor* editor)
   m_thumbnailsPrefConn = docPref.thumbnails.AfterChange.connect(
     base::Bind<void>(&Timeline::onThumbnailsPrefChange, this));
 
+  setZoom(docPref.thumbnails.zoom());
+
   // If we are already in the same position as the "editor", we don't
   // need to update the at all timeline.
   if (m_document == site.document() &&
@@ -893,8 +901,7 @@ bool Timeline::onProcessMessage(Message* msg)
       break;
 
     case kTouchMagnifyMessage:
-      m_zoom = m_zoom + m_zoom * static_cast<ui::TouchMessage*>(msg)->magnification();
+      setZoom(m_zoom + m_zoom * static_cast<ui::TouchMessage*>(msg)->magnification());
-      m_zoom = MID(1.0, m_zoom, 10.0);
       invalidate();
       break;
   }

src/app/ui/timeline.h

@@ -265,6 +265,7 @@ namespace app {
     void updateCelOverlayBounds(const Hit& hit);
     void drawCelOverlay(ui::Graphics* g);
     void onThumbnailsPrefChange();
+    void setZoom(double zoom);
 
     ui::ScrollBar m_hbar;
     ui::ScrollBar m_vbar;