Don't shrink the image when the aspect ratio changes

include/rqt_image_view/ratio_layouted_frame.h

@@ -70,6 +70,8 @@ class RatioLayoutedFrame
 
   void resizeToFitAspectRatio();
 
+  void setOuterLayout(QHBoxLayout* outer_layout);
+
   void setInnerFrameMinimumSize(const QSize& size);
 
   void setInnerFrameMaximumSize(const QSize& size);
@@ -98,6 +100,8 @@ protected slots:
 
   void mousePressEvent(QMouseEvent * mouseEvent);
 
+  QHBoxLayout* outer_layout_;
+
   QSize aspect_ratio_;
 
   QImage qimage_;

src/rqt_image_view/image_view.cpp

@@ -86,6 +86,8 @@ void ImageView::initPlugin(qt_gui_cpp::PluginContext& context)
   }
   pub_topic_custom_ = false;
 
+  ui_.image_frame->setOuterLayout(ui_.image_layout);
+
   QRegExp rx("([a-zA-Z/][a-zA-Z0-9_/]*)?"); //see http://www.ros.org/wiki/ROS/Concepts#Names.Valid_Names (but also accept an empty field)
   ui_.publish_click_location_topic_line_edit->setValidator(new QRegExpValidator(rx, this));
   connect(ui_.publish_click_location_check_box, SIGNAL(toggled(bool)), this, SLOT(onMousePublish(bool)));
@@ -434,8 +436,10 @@ void ImageView::callbackImage(const sensor_msgs::Image::ConstPtr& msg)
   if (!ui_.zoom_1_push_button->isEnabled())
   {
     ui_.zoom_1_push_button->setEnabled(true);
-    onZoom1(ui_.zoom_1_push_button->isChecked());
   }
+  // Need to update the zoom 1 every new image in case the image aspect ratio changed,
+  // though could check and see if the aspect ratio changed or not.
+  onZoom1(ui_.zoom_1_push_button->isChecked());
 }
 }
 

src/rqt_image_view/image_view.ui

@@ -157,7 +157,7 @@
     </widget>
    </item>
    <item>
-    <layout class="QHBoxLayout" name="horizontalLayout_2" stretch="1,0">
+    <layout class="QHBoxLayout" name="image_layout" stretch="1,0">
      <property name="spacing">
       <number>0</number>
      </property>

src/rqt_image_view/ratio_layouted_frame.cpp

@@ -39,6 +39,7 @@ namespace rqt_image_view {
 
 RatioLayoutedFrame::RatioLayoutedFrame(QWidget* parent, Qt::WindowFlags flags)
   : QFrame()
+  , outer_layout_(NULL)
   , aspect_ratio_(4, 3)
   , smoothImage_(false)
 {
@@ -68,7 +69,6 @@ void RatioLayoutedFrame::setImage(const QImage& image)//, QMutex* image_mutex)
   qimage_mutex_.lock();
   qimage_ = image.copy();
   qimage_mutex_.unlock();
-  setAspectRatio(qimage_.width(), qimage_.height());
   emit delayed_update();
 }
 
@@ -77,26 +77,48 @@ void RatioLayoutedFrame::resizeToFitAspectRatio()
   QRect rect = contentsRect();
 
   // reduce longer edge to aspect ration
-  double width = double(rect.width());
-  double height = double(rect.height());
-  if (width * aspect_ratio_.height() / height > aspect_ratio_.width())
+  double width;
+  double height;
+
+  if (outer_layout_)
+  {
+    width = outer_layout_->contentsRect().width();
+    height = outer_layout_->contentsRect().height();
+  }
+  else
+  {
+    // if outer layout isn't available, this will use the old
+    // width and height, but this can shrink the display image if the
+    // aspect ratio changes.
+    width = rect.width();
+    height = rect.height();
+  }
+
+  double layout_ar = width / height;
+  const double image_ar = double(aspect_ratio_.width()) / double(aspect_ratio_.height());
+  if (layout_ar > image_ar)
   {
     // too large width
-    width = height * aspect_ratio_.width() / aspect_ratio_.height();
-    rect.setWidth(int(width + 0.5));
+    width = height * image_ar;
   }
   else
   {
     // too large height
-    height = width * aspect_ratio_.height() / aspect_ratio_.width();
-    rect.setHeight(int(height + 0.5));
+    height = width / image_ar;
   }
+  rect.setWidth(int(width + 0.5));
+  rect.setHeight(int(height + 0.5));
 
   // resize taking the border line into account
   int border = lineWidth();
   resize(rect.width() + 2 * border, rect.height() + 2 * border);
 }
 
+void RatioLayoutedFrame::setOuterLayout(QHBoxLayout* outer_layout)
+{
+  outer_layout_ = outer_layout;
+}
+
 void RatioLayoutedFrame::setInnerFrameMinimumSize(const QSize& size)
 {
   int border = lineWidth();
@@ -136,6 +158,7 @@ void RatioLayoutedFrame::paintEvent(QPaintEvent* event)
   qimage_mutex_.lock();
   if (!qimage_.isNull())
   {
+    setAspectRatio(qimage_.width(), qimage_.height());
     resizeToFitAspectRatio();
     // TODO: check if full draw is really necessary
     //QPaintEvent* paint_event = dynamic_cast<QPaintEvent*>(event);