Merge pull request #4632: FEAT(client): Easier pasting of images

Currently pasting or dragging and dropping images in the Mumble chat is
difficult because:

1. They are rejected because they exceed the allowed size. As a user I
    would not expect it to transmitted losslessly but I would hope that the
    client compresses it to a size the server allows.
2. Images are rejected because the server does not allow html. When
    inserting an image via drag and drop you aren't notified what went
    wrong.

src/mumble/CustomElements.cpp

@@ -180,43 +180,48 @@ void ChatbarTextEdit::insertFromMimeData(const QMimeData *source) {
 }
 
 bool ChatbarTextEdit::sendImagesFromMimeData(const QMimeData *source) {
-	if (source->hasImage()) {
-		// Process the image pasted onto the chatbar.
-		if (g.bAllowHTML) {
+	if (g.bAllowHTML) {
+		if (source->hasImage()) {
+			// Process the image pasted onto the chatbar.
 			QImage image = qvariant_cast< QImage >(source->imageData());
-
-			QString imgHtml = QLatin1String("<br />") + Log::imageToImg(image);
-
-			if ((g.uiImageLength == 0) || static_cast< unsigned int >(imgHtml.length()) < g.uiImageLength) {
-				emit pastedImage(imgHtml);
+			if (emitPastedImage(image)) {
 				return true;
 			} else {
 				g.l->log(Log::Information, tr("Unable to send image: too large."));
+				return false;
 			}
-		}
-	} else if (source->hasUrls()) {
-		// Process the files dropped onto the chatbar. URLs here should be understood as the URIs of files.
-		QList< QUrl > urlList = source->urls();
 
-		int count = 0;
-		for (int i = 0; i < urlList.size(); ++i) {
-			QString path = urlList[i].toLocalFile();
-			QImage image(path);
+		} else if (source->hasUrls()) {
+			// Process the files dropped onto the chatbar. URLs here should be understood as the URIs of files.
+			QList< QUrl > urlList = source->urls();
 
-			if (image.isNull())
-				continue;
+			int count = 0;
+			for (int i = 0; i < urlList.size(); ++i) {
+				QString path = urlList[i].toLocalFile();
+				QImage image(path);
 
-			QString imgHtml = QLatin1String("<br />") + Log::imageToImg(image);
-
-			if (static_cast< unsigned int >(imgHtml.length()) < g.uiImageLength) {
-				emit pastedImage(imgHtml);
-				++count;
-			} else {
-				g.l->log(Log::Information, tr("Unable to send image %1: too large.").arg(path));
+				if (image.isNull())
+					continue;
+				if (emitPastedImage(image)) {
+					++count;
+				} else {
+					g.l->log(Log::Information, tr("Unable to send image %1: too large.").arg(path));
+				}
 			}
-		}
 
-		return (count > 0);
+			return (count > 0);
+		}
+	}
+	g.l->log(Log::Information, tr("This server does not allow sending images."));
+	return false;
+}
+
+bool ChatbarTextEdit::emitPastedImage(QImage image) {
+	QString processedImage = Log::imageToImg(image, g.uiImageLength);
+	if (processedImage.length() > 0) {
+		QString imgHtml = QLatin1String("<br />") + processedImage;
+		emit pastedImage(imgHtml);
+		return true;
 	}
 	return false;
 }

src/mumble/CustomElements.h

@@ -53,6 +53,7 @@ protected:
 	void resizeEvent(QResizeEvent *e) Q_DECL_OVERRIDE;
 	void insertFromMimeData(const QMimeData *source) Q_DECL_OVERRIDE;
 	bool sendImagesFromMimeData(const QMimeData *source);
+	bool emitPastedImage(QImage image);
 
 public:
 	void setDefaultText(const QString &, bool = false);

src/mumble/Log.cpp

@@ -522,38 +522,30 @@ QString Log::imageToImg(const QByteArray &format, const QByteArray &image) {
 	return QString::fromLatin1("<img src=\"data:image/%1;base64,%2\" />").arg(fmt).arg(QLatin1String(encoded));
 }
 
-QString Log::imageToImg(QImage img) {
+QString Log::imageToImg(QImage img, int maxSize) {
 	if ((img.width() > 480) || (img.height() > 270)) {
 		img = img.scaled(480, 270, Qt::KeepAspectRatio, Qt::SmoothTransformation);
 	}
 
 	int quality       = 100;
-	QByteArray format = "PNG";
+	QByteArray format = "JPEG";
 
 	QByteArray qba;
-	{
-		QBuffer qb(&qba);
-		qb.open(QIODevice::WriteOnly);
-
-		QImageWriter imgwrite(&qb, format);
-		imgwrite.write(img);
-	}
-
-	while ((qba.length() >= 65536) && (quality > 0)) {
+	QString result;
+	while (quality > 0) {
 		qba.clear();
 		QBuffer qb(&qba);
 		qb.open(QIODevice::WriteOnly);
 
-		format = "JPEG";
-
 		QImageWriter imgwrite(&qb, format);
 		imgwrite.setQuality(quality);
 		imgwrite.write(img);
+		result = imageToImg(format, qba);
+		if (result.length() < maxSize || maxSize == 0) {
+			return result;
+		}
 		quality -= 10;
 	}
-	if (qba.length() < 65536) {
-		return imageToImg(format, qba);
-	}
 	return QString();
 }
 

src/mumble/Log.h

@@ -125,7 +125,7 @@ public:
 	void clearIgnore();
 	static QString validHtml(const QString &html, QTextCursor *tc = nullptr);
 	static QString imageToImg(const QByteArray &format, const QByteArray &image);
-	static QString imageToImg(QImage img);
+	static QString imageToImg(QImage img, int maxSize = 0);
 	static QString msgColor(const QString &text, LogColorType t);
 	static QString formatClientUser(ClientUser *cu, LogColorType t, const QString &displayName = QString());
 	static QString formatChannel(::Channel *c);

src/mumble/mumble_en.ts

@@ -2694,6 +2694,10 @@ Are you sure you wish to replace your certificate?
         <source>Unable to send image %1: too large.</source>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>This server does not allow sending images.</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>ClientUser</name>