started zoom tool

app/widget/timelineview/timelineview.cpp

@@ -39,6 +39,7 @@ TimelineView::TimelineView(QWidget *parent) :
   ripple_tool_(this),
   razor_tool_(this),
   hand_tool_(this),
+  zoom_tool_(this),
   playhead_(0)
 {
   setScene(&scene_);
@@ -220,7 +221,7 @@ TimelineView::Tool *TimelineView::GetActiveTool()
   case olive::tool::kHand:
     return &hand_tool_;
   case olive::tool::kZoom:
-    return nullptr; // FIXME: Implement
+    return &zoom_tool_;
   case olive::tool::kTransition:
     return nullptr; // FIXME: Implement
   case olive::tool::kRecord:

app/widget/timelineview/timelineview.h

@@ -227,6 +227,16 @@ private:
     QPoint scrollbar_start_;
   };
 
+  class ZoomTool : public Tool
+  {
+  public:
+    ZoomTool(TimelineView* parent);
+
+    virtual void MousePress(QMouseEvent *event);
+    virtual void MouseMove(QMouseEvent *event);
+    virtual void MouseRelease(QMouseEvent *event);
+  };
+
   Tool* GetActiveTool();
 
   int GetTrackY(int track_index);
@@ -237,6 +247,7 @@ private:
   RippleTool ripple_tool_;
   RazorTool razor_tool_;
   HandTool hand_tool_;
+  ZoomTool zoom_tool_;
 
   void AddGhost(TimelineViewGhostItem* ghost);
 

app/widget/timelineview/tool/CMakeLists.txt

@@ -22,5 +22,6 @@ set(OLIVE_SOURCES
   widget/timelineview/tool/razor.cpp
   widget/timelineview/tool/ripple.cpp
   widget/timelineview/tool/tool.cpp
+  widget/timelineview/tool/zoom.cpp
   PARENT_SCOPE
 )

app/widget/timelineview/tool/zoom.cpp

@@ -0,0 +1,47 @@
+/***
+
+  Olive - Non-Linear Video Editor
+  Copyright (C) 2019 Olive Team
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU 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/>.
+
+***/
+
+#include "widget/timelineview/timelineview.h"
+
+TimelineView::ZoomTool::ZoomTool(TimelineView* parent) :
+  Tool(parent)
+{
+}
+
+void TimelineView::ZoomTool::MousePress(QMouseEvent *event)
+{
+  Q_UNUSED(event)
+}
+
+void TimelineView::ZoomTool::MouseMove(QMouseEvent *event)
+{
+  Q_UNUSED(event)
+}
+
+void TimelineView::ZoomTool::MouseRelease(QMouseEvent *event)
+{
+  if (event->modifiers() & Qt::AltModifier) {
+    // Zoom out if the user clicks while holding Alt
+    parent()->SetScale(parent()->scale_ * 0.5);
+  } else {
+    // Otherwise zoom in
+    parent()->SetScale(parent()->scale_ * 2);
+  }
+}