Author Color Fixes

Author color is now cached so that it will not be re-calculated
each time a new message is posted.  This cache gets cleared when
the theme is changed.

Additionally, the author color is now automatically refreshed
when the theme is changed, fixing the issue where you had to
change rooms before the colors would switch.

src/ChatPage.h

@@ -148,6 +148,7 @@ signals:
                            const QImage &icon);
 
         void updateGroupsInfo(const mtx::responses::JoinedGroups &groups);
+        void themeChanged();
 
 private slots:
         void showUnreadMessageNotification(int count);

src/MainWindow.cpp

@@ -112,7 +112,11 @@ MainWindow::MainWindow(QWidget *parent)
 
         connect(
           userSettingsPage_, SIGNAL(trayOptionChanged(bool)), trayIcon_, SLOT(setVisible(bool)));
-
+        connect(userSettingsPage_, &UserSettingsPage::themeChanged, this, [this]() {
+                utils::clearAuthorColors();
+        });
+        connect(
+          userSettingsPage_, &UserSettingsPage::themeChanged, chat_page_, &ChatPage::themeChanged);
         connect(trayIcon_,
                 SIGNAL(activated(QSystemTrayIcon::ActivationReason)),
                 this,

src/UserSettingsPage.cpp

@@ -379,7 +379,10 @@ UserSettingsPage::UserSettingsPage(QSharedPointer<UserSettings> settings, QWidge
 
         connect(themeCombo_,
                 static_cast<void (QComboBox::*)(const QString &)>(&QComboBox::activated),
-                [this](const QString &text) { settings_->setTheme(text.toLower()); });
+                [this](const QString &text) {
+                        settings_->setTheme(text.toLower());
+                        emit themeChanged();
+                });
         connect(scaleFactorCombo_,
                 static_cast<void (QComboBox::*)(const QString &)>(&QComboBox::activated),
                 [](const QString &factor) { utils::setScaleFactor(factor.toFloat()); });

src/UserSettingsPage.h

@@ -132,6 +132,7 @@ protected:
 signals:
         void moveBack();
         void trayOptionChanged(bool value);
+        void themeChanged();
 
 private slots:
         void importSessionKeys();

src/Utils.cpp

@@ -15,6 +15,8 @@
 
 using TimelineEvent = mtx::events::collections::TimelineEvents;
 
+QHash<QString, QString> authorColors_;
+
 QString
 utils::localUser()
 {
@@ -511,6 +513,28 @@ utils::luminance(const QColor &col)
         return lum;
 }
 
+void
+utils::clearAuthorColors()
+{
+        authorColors_.clear();
+}
+
+QString
+utils::getAuthorColor(const QString &author)
+{
+        if (authorColors_.contains(author)) {
+                return authorColors_[author];
+        } else {
+                return "";
+        }
+}
+
+void
+utils::addAuthorColor(const QString &author, const QString &color)
+{
+        authorColors_[author] = color;
+}
+
 void
 utils::centerWidget(QWidget *widget, QWidget *parent)
 {

src/Utils.h

@@ -246,6 +246,18 @@ computeContrast(const qreal &one, const qreal &two);
 qreal
 luminance(const QColor &col);
 
+//! Clear the author color hashmap
+void
+clearAuthorColors();
+
+//! Get the given QString from the authorColors hash
+QString
+getAuthorColor(const QString &author);
+
+//! Put the given QString into the authorColor hash
+void
+addAuthorColor(const QString &author, const QString &color);
+
 //! Center a widget in relation to another widget.
 void
 centerWidget(QWidget *widget, QWidget *parent);

src/timeline/TimelineItem.cpp

@@ -192,7 +192,8 @@ TimelineItem::init()
                                   emit eventRedacted(event_id_);
                           });
         });
-
+        connect(
+          ChatPage::instance(), &ChatPage::themeChanged, this, &TimelineItem::refreshAuthorColor);
         connect(markAsRead_, &QAction::triggered, this, &TimelineItem::sendReadReceipt);
         connect(viewRawMessage_, &QAction::triggered, this, &TimelineItem::openRawMessageViewer);
 
@@ -603,6 +604,21 @@ TimelineItem::generateBody(const QString &body)
         });
 }
 
+void
+TimelineItem::refreshAuthorColor()
+{
+        if (userName_) {
+                QString userColor = utils::getAuthorColor(userName_->text());
+                if (userColor.isEmpty()) {
+                        qApp->style()->polish(this);
+                        // generate user's unique color.
+                        auto backCol = backgroundColor().name();
+                        userColor = utils::generateContrastingHexColor(userName_->text(), backCol);
+                        utils::addAuthorColor(userName_->text(), userColor);
+                }
+                userName_->setStyleSheet("QLabel { color : " + userColor + "; }");
+        }
+}
 // The username/timestamp is displayed along with the message body.
 void
 TimelineItem::generateBody(const QString &user_id, const QString &displayname, const QString &body)
@@ -639,10 +655,14 @@ TimelineItem::generateUserName(const QString &user_id, const QString &displaynam
 
         // TimelineItem isn't displayed.  This forces the QSS to get
         // loaded.
-        qApp->style()->polish(this);
-        // generate user's unique color.
-        auto backCol   = backgroundColor().name();
-        auto userColor = utils::generateContrastingHexColor(user_id, backCol);
+        QString userColor = utils::getAuthorColor(user_id);
+        if (userColor.isEmpty()) {
+                qApp->style()->polish(this);
+                // generate user's unique color.
+                auto backCol = backgroundColor().name();
+                userColor    = utils::generateContrastingHexColor(user_id, backCol);
+                utils::addAuthorColor(user_id, userColor);
+        }
         userName_->setStyleSheet("QLabel { color : " + userColor + "; }");
 
         auto filter = new UserProfileFilter(user_id, userName_);

src/timeline/TimelineItem.h

@@ -227,6 +227,9 @@ signals:
         void eventRedacted(const QString &event_id);
         void redactionFailed(const QString &msg);
 
+public slots:
+        void refreshAuthorColor();
+
 protected:
         void paintEvent(QPaintEvent *event) override;
         void contextMenuEvent(QContextMenuEvent *event) override;