Fix line break issue on timeline with long words

fixes #193

include/timeline/TimelineItem.h

@@ -17,6 +17,7 @@
 
 #pragma once
 
+#include <QAbstractTextDocumentLayout>
 #include <QDateTime>
 #include <QHBoxLayout>
 #include <QLabel>
@@ -24,6 +25,8 @@
 #include <QSettings>
 #include <QStyle>
 #include <QStyleOption>
+#include <QTextBrowser>
+#include <QTimer>
 
 #include "AvatarProvider.h"
 #include "RoomInfoListItem.h"
@@ -39,6 +42,48 @@ class VideoItem;
 class FileItem;
 class Avatar;
 
+class TextLabel : public QTextBrowser
+{
+        Q_OBJECT
+
+public:
+        TextLabel(const QString &text, QWidget *parent = 0)
+          : QTextBrowser(parent)
+        {
+                setText(text);
+                setOpenExternalLinks(true);
+
+                // Make it look and feel like an ordinary label.
+                setReadOnly(true);
+                setFrameStyle(QFrame::NoFrame);
+                QPalette pal = palette();
+                pal.setColor(QPalette::Base, Qt::transparent);
+                setPalette(pal);
+
+                // Wrap anywhere but prefer words, adjust minimum height on the fly.
+                setLineWrapMode(QTextEdit::WidgetWidth);
+                setWordWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
+                connect(document()->documentLayout(),
+                        &QAbstractTextDocumentLayout::documentSizeChanged,
+                        this,
+                        &TextLabel::adjustHeight);
+                document()->setDocumentMargin(0);
+
+                setFixedHeight(document()->size().height());
+        }
+
+        QSize sizeHint() const override
+        {
+                ensurePolished();
+                return document()->size().toSize();
+        }
+
+        void wheelEvent(QWheelEvent *event) override { event->ignore(); }
+
+private slots:
+        void adjustHeight(const QSizeF &size) { setFixedHeight(size.height()); }
+};
+
 class TimelineItem : public QWidget
 {
         Q_OBJECT
@@ -174,7 +219,7 @@ private:
         QLabel *timestamp_;
         QLabel *checkmark_;
         QLabel *userName_;
-        QLabel *body_;
+        TextLabel *body_;
 };
 
 template<class Widget>

src/timeline/TimelineItem.cc

@@ -18,7 +18,6 @@
 #include <QContextMenuEvent>
 #include <QFontDatabase>
 #include <QMenu>
-#include <QTextEdit>
 #include <QTimer>
 
 #include "Avatar.h"
@@ -426,14 +425,9 @@ TimelineItem::generateBody(const QString &body)
 {
         QString content("<span>%1</span>");
 
-        body_ = new QLabel(this);
+        body_ = new TextLabel(content.arg(replaceEmoji(body)), this);
         body_->setFont(font_);
-        body_->setWordWrap(true);
-        body_->setText(content.arg(replaceEmoji(body)));
-        body_->setMargin(0);
-
         body_->setTextInteractionFlags(Qt::TextSelectableByMouse | Qt::TextBrowserInteraction);
-        body_->setOpenExternalLinks(true);
 }
 
 // The username/timestamp is displayed along with the message body.