added auto-selection of aspect ratio in posts view

retroshare-gui/src/gui/gxschannels/GxsChannelPostThumbnail.cpp

@@ -158,6 +158,20 @@ void ChannelPostThumbnailView::init(const RsGxsChannelPost& post)
     update();
 }
 
+ChannelPostThumbnailView::AspectRatio ChannelPostThumbnailView::bestAspectRatio()
+{
+    if(mPostImage->originalImage().isNull())
+        return ASPECT_RATIO_1_1;
+
+    float as = mPostImage->originalImage().height() / (float)mPostImage->originalImage().width() ;
+
+    if(as < 0.8)
+        return ASPECT_RATIO_16_9;
+    else if(as < 1.15)
+        return ASPECT_RATIO_1_1;
+    else
+        return ASPECT_RATIO_2_3;
+}
 QSize ChannelPostThumbnailView::actualSize() const
 {
     QFontMetricsF fm(font());

retroshare-gui/src/gui/gxschannels/GxsChannelPostThumbnail.h

@@ -46,6 +46,8 @@ public:
     QPixmap extractCroppedScaledPicture() const;
     void updateView();
 
+    const QPixmap& originalImage() const { return mFullImage ; }
+
 protected:
     void mousePressEvent(QMouseEvent *ev) override;
     void mouseReleaseEvent(QMouseEvent *ev) override;
@@ -108,6 +110,13 @@ public:
     // The label however has a correct size. It seems that Qt doesn't like widgets with horizontal aspect ratio and forces the size accordingly.
 
     QSize actualSize() const ;
+
+    /*!
+     * \brief bestAspectRatio
+     * 			Computes the preferred aspect ratio for the image in the post. The default is 1:1.
+     * \return the prefered aspect ratio
+     */
+    AspectRatio bestAspectRatio() ;
 private:
     static const float DEFAULT_SIZE_IN_FONT_HEIGHT ;
 

retroshare-gui/src/gui/gxschannels/GxsChannelPostsModel.h

@@ -108,6 +108,7 @@ public:
 	std::vector<std::pair<time_t,RsGxsMessageId> > getPostVersions(const RsGxsMessageId& mid) const;
 
     uint32_t getNumberOfPosts() { return mPosts.size() ; }
+    const RsGxsChannelPost& post(uint32_t i) const { return mPosts[i]; }
 
     // This method will asynchroneously update the data
 	void updateChannel(const RsGxsGroupId& channel_group_id);

retroshare-gui/src/gui/gxschannels/GxsChannelPostsWidgetWithModel.cpp

@@ -145,13 +145,13 @@ void ChannelPostDelegate::paint(QPainter * painter, const QStyleOptionViewItem &
 
         pixmap = pixmap.copy(QRect(0,0,w.actualSize().width(),w.actualSize().height()));
 
-        if(index.row()==0 && index.column()==0)
+//		if(index.row()==0 && index.column()==0)
-    {
+//		{
-        QFile file("yourFile.png");
+//			QFile file("yourFile.png");
-        file.open(QIODevice::WriteOnly);
+//			file.open(QIODevice::WriteOnly);
-        pixmap.save(&file, "PNG");
+//			pixmap.save(&file, "PNG");
-                file.close();
+//			file.close();
-    }
+//		}
 
         if(mUseGrid || index.column()==0)
         {
@@ -787,6 +787,25 @@ void GxsChannelPostsWidgetWithModel::postChannelPostLoad()
     ui->channelFiles_TV->sortByColumn(0, Qt::AscendingOrder);
 
     ui->infoPosts->setText(QString::number(mChannelPostsModel->getNumberOfPosts()) + " / " + QString::number(mGroup.mMeta.mVisibleMsgCount));
+
+    // now compute aspect ratio for posts. We do that by looking at the 5 latest posts and compute the best aspect ratio for them.
+
+    std::vector<uint32_t> ar_votes(3,0);
+
+    for(uint32_t i=0;i<std::min(mChannelPostsModel->getNumberOfPosts(),5u);++i)
+    {
+        const RsGxsChannelPost& post = mChannelPostsModel->post(i);
+        ChannelPostThumbnailView v(post,ChannelPostThumbnailView::FLAG_SHOW_TEXT);
+
+        ++ar_votes[ static_cast<uint32_t>( v.bestAspectRatio() )];
+    }
+    int best=0;
+    for(uint32_t i=0;i<3;++i)
+        if(ar_votes[i] > ar_votes[best])
+            best = i;
+
+    mChannelPostsDelegate->setAspectRatio(static_cast<ChannelPostThumbnailView::AspectRatio>(best));
+    mChannelPostsModel->triggerViewUpdate();
 }
 
 void GxsChannelPostsWidgetWithModel::updateDisplay(bool complete)