Request inline images in the right size and anti-alias them

- If an inline image has specified a height, add parameters to the
  image:// URI.
- Add scaled to the parameters, the images would be cropped otherwise.
- Extract the height from image:// URI and use it for requestSize.
- Use scaledToHeight instead of scaled.

2 files changed, 39 insertions, 9 deletions

diff --git a/src/MxcImageProvider.cpp b/src/MxcImageProvider.cpp

index 4834c2fc..97cbfff3 100644
--- a/src/MxcImageProvider.cpp
+++ b/src/MxcImageProvider.cpp
@@ -27,6 +27,7 @@ MxcImageProvider::requestImageResponse(const QString &id, const QSize &requested
     auto id_      = id;
     bool crop     = true;
     double radius = 0;
+    auto size     = requestedSize;
 
     auto queryStart = id.lastIndexOf('?');
     if (queryStart != -1) {
@@ -39,11 +40,14 @@ MxcImageProvider::requestImageResponse(const QString &id, const QSize &requested
                 crop = false;
             } else if (b.startsWith("radius=")) {
                 radius = b.mid(7).toDouble();
+            } else if (b.startsWith("height=")) {
+                size.setHeight(b.mid(7).toInt());
+                size.setWidth(0);
             }
         }
     }
 
-    return new MxcImageResponse(id_, crop, radius, requestedSize);
+    return new MxcImageResponse(id_, crop, radius, size);
 }
 
 void
@@ -120,7 +124,9 @@ MxcImageProvider::download(const QString &id,
         if (fileInfo.exists()) {
             QImage image = utils::readImageFromFile(fileInfo.absoluteFilePath());
             if (!image.isNull()) {
-                image = image.scaled(requestedSize, Qt::KeepAspectRatio, Qt::SmoothTransformation);
+                if (requestedSize != image.size()) {
+                    image = image.scaledToHeight(requestedSize.height(), Qt::SmoothTransformation);
+                }
 
                 if (radius != 0) {
                     image = clipRadius(std::move(image), radius);
@@ -151,8 +157,10 @@ MxcImageProvider::download(const QString &id,
               auto data    = QByteArray(res.data(), (int)res.size());
               QImage image = utils::readImage(data);
               if (!image.isNull()) {
-                  image =
-                    image.scaled(requestedSize, Qt::KeepAspectRatio, Qt::SmoothTransformation);
+                  if (requestedSize != image.size()) {
+                      image =
+                        image.scaledToHeight(requestedSize.height(), Qt::SmoothTransformation);
+                  }
 
                   if (radius != 0) {
                       image = clipRadius(std::move(image), radius);
diff --git a/src/timeline/TimelineModel.cpp b/src/timeline/TimelineModel.cpp

index b9941dfa..9696dffb 100644
--- a/src/timeline/TimelineModel.cpp
+++ b/src/timeline/TimelineModel.cpp
@@ -561,15 +561,37 @@ TimelineModel::data(const mtx::events::collections::TimelineEvents &event, int r
         }
 
         // TODO(Nico): Don't parse html with a regex
-        const static QRegularExpression matchImgUri("(<img [^>]*)src=\"mxc://([^\"]*)\"([^>]*>)");
-        formattedBody_.replace(matchImgUri, "\\1 src=\"image://mxcImage/\\2\"\\3");
-        // Same regex but for single quotes around the src
-        const static QRegularExpression matchImgUri2("(<img [^>]*)src=\'mxc://([^\']*)\'([^>]*>)");
-        formattedBody_.replace(matchImgUri2, "\\1 src=\"image://mxcImage/\\2\"\\3");
         const static QRegularExpression matchEmoticonHeight(
           "(<img data-mx-emoticon [^>]*)height=\"([^\"]*)\"([^>]*>)");
         formattedBody_.replace(matchEmoticonHeight, QString("\\1 height=\"%1\"\\3").arg(ascent));
 
+        const static QRegularExpression matchIsImg("<img [^>]+>");
+        auto itIsImg = matchIsImg.globalMatch(formattedBody_);
+        while (itIsImg.hasNext()) {
+            const QString curImg = itIsImg.next().captured(0);
+
+            // Construct image parameters later used by MxcImageProvider.
+            QString imgParams;
+            if (curImg.contains("height")) {
+                const static QRegularExpression matchImgHeight("height=[\"\']?(\\d+)[\"\']?");
+                const auto height = matchImgHeight.match(curImg).captured(1).toInt();
+                imgParams         = QString("?scale&height=%1").arg(height);
+            }
+
+            // Replace src in current <img>.
+            auto imgReplacement = curImg;
+            const static QRegularExpression matchImgUri("src=\"mxc://([^\"]*)\"");
+            imgReplacement.replace(matchImgUri,
+                                   QString("src=\"image://mxcImage/\\1%1\"").arg(imgParams));
+            // Same regex but for single quotes around the src
+            const static QRegularExpression matchImgUri2("src=\'mxc://([^\']*)\'");
+            imgReplacement.replace(matchImgUri2,
+                                   QString("src=\'image://mxcImage/\\1%1\'").arg(imgParams));
+
+            // Replace <img> in formattedBody_ with our new <img>.
+            formattedBody_.replace(curImg, imgReplacement);
+        }
+
         return QVariant(
           utils::replaceEmoji(utils::linkifyMessage(utils::escapeBlacklistedHtml(formattedBody_))));
     }