viewer: allow customizing subtitle font

Fixes #1980

app/config/config.cpp

@@ -108,6 +108,11 @@ void Config::SetDefaults()
   SetEntryInternal(QStringLiteral("DefaultAudioTransition"), NodeValue::kText, QStringLiteral("org.olivevideoeditor.Olive.crossdissolve"));
   SetEntryInternal(QStringLiteral("DefaultTransitionLength"), NodeValue::kRational, QVariant::fromValue(rational(1)));
 
+  SetEntryInternal(QStringLiteral("DefaultSubtitleSize"), NodeValue::kInt, 48);
+  SetEntryInternal(QStringLiteral("DefaultSubtitleFamily"), NodeValue::kText, QString());
+  SetEntryInternal(QStringLiteral("DefaultSubtitleWeight"), NodeValue::kInt, QFont::Bold);
+  SetEntryInternal(QStringLiteral("AntialiasSubtitles"), NodeValue::kBoolean, true);
+
   SetEntryInternal(QStringLiteral("AutoCacheDelay"), NodeValue::kInt, 1000);
 
   SetEntryInternal(QStringLiteral("CatColor0"), NodeValue::kInt, ColorCoding::kRed);

app/widget/viewer/viewer.cpp

@@ -21,6 +21,7 @@
 #include "viewer.h"
 
 #include <QDateTime>
+#include <QFontDialog>
 #include <QGuiApplication>
 #include <QInputDialog>
 #include <QLabel>
@@ -32,7 +33,6 @@
 
 #include "audio/audiomanager.h"
 #include "common/clamp.h"
-#include "common/power.h"
 #include "common/ratiodialog.h"
 #include "common/timecodefunctions.h"
 #include "config/config.h"
@@ -41,10 +41,9 @@
 #include "node/generator/shape/shapenodebase.h"
 #include "node/project/project.h"
 #include "render/rendermanager.h"
-#include "task/taskmanager.h"
 #include "viewerpreventsleep.h"
+#include "widget/audiomonitor/audiomonitor.h"
 #include "widget/menu/menu.h"
-#include "window/mainwindow/mainwindow.h"
 #include "widget/nodeparamview/nodeparamviewundo.h"
 #include "widget/timelinewidget/tool/add.h"
 #include "widget/timeruler/timeruler.h"
@@ -547,6 +546,20 @@ void ViewerWidget::HandleFirstRequeueDestroy()
   }
 }
 
+void ViewerWidget::ShowSubtitleProperties()
+{
+  QFont f(OLIVE_CONFIG("DefaultSubtitleFamily").toString(), OLIVE_CONFIG("DefaultSubtitleSize").toInt(), OLIVE_CONFIG("DefaultSubtitleWeight").toInt());
+  QFontDialog fd(f, this);
+
+  if (fd.exec() == QDialog::Accepted) {
+    f = fd.selectedFont();
+    OLIVE_CONFIG("DefaultSubtitleSize") = f.pointSize();
+    OLIVE_CONFIG("DefaultSubtitleFamily") = f.family();
+    OLIVE_CONFIG("DefaultSubtitleWeight") = f.weight();
+    display_widget_->update();
+  }
+}
+
 void ViewerWidget::CloseAudioProcessor()
 {
   audio_processor_.Close();
@@ -1309,10 +1322,26 @@ void ViewerWidget::ShowContextMenu(const QPoint &pos)
   }
 
   if (context_menu_widget_ == display_widget_) {
-    QAction* show_subtitles_action = menu.addAction(tr("Show Subtitles"));
+    auto subtitle_menu = new Menu(tr("Subtitles"), &menu);
+    menu.addMenu(subtitle_menu);
+
+    QAction* show_subtitles_action = subtitle_menu->addAction(tr("Show Subtitles"));
     show_subtitles_action->setCheckable(true);
     show_subtitles_action->setChecked(display_widget_->GetShowSubtitles());
     connect(show_subtitles_action, &QAction::triggered, display_widget_, &ViewerDisplayWidget::SetShowSubtitles);
+
+    subtitle_menu->addSeparator();
+
+    auto subtitle_font_properties = subtitle_menu->addAction(tr("Subtitle Properties"));
+    connect(subtitle_font_properties, &QAction::triggered, this, &ViewerWidget::ShowSubtitleProperties);
+
+    auto subtitle_antialias = subtitle_menu->addAction(tr("Use Anti-aliasing"));
+    subtitle_antialias->setCheckable(true);
+    subtitle_antialias->setChecked(OLIVE_CONFIG("AntialiasSubtitles").toBool());
+    connect(subtitle_antialias, &QAction::triggered, this, [this](bool e){
+      OLIVE_CONFIG("AntialiasSubtitles") = e;
+      display_widget_->update();
+    });
   }
 
   menu.exec(static_cast<QWidget*>(sender())->mapToGlobal(pos));

app/widget/viewer/viewer.h

@@ -352,6 +352,8 @@ private slots:
 
   void HandleFirstRequeueDestroy();
 
+  void ShowSubtitleProperties();
+
 };
 
 }

app/widget/viewer/viewerdisplay.cpp

@@ -463,45 +463,78 @@ void ViewerDisplayWidget::OnPaint()
     const QVector<Track*> &subtitle_tracklist = subtitle_tracks_->track_list(Track::kSubtitle)->GetTracks();
 
     if (!subtitle_tracklist.empty()) {
-      QPainter p(paint_device());
+      QPainterPath path;
 
       QTransform transform = GenerateWorldTransform();
       QRect bounding_box = transform.mapRect(rect());
 
+      QFont f;
+      qreal font_sz = OLIVE_CONFIG("DefaultSubtitleSize").toInt();
+      {
+        // Scale font size by transform
+        QTransform display_transform = GenerateDisplayTransform();
+        font_sz *= display_transform.m11();
+      }
+      f.setPointSizeF(font_sz);
+
+      QString family = OLIVE_CONFIG("DefaultSubtitleFamily").toString();
+      if (!family.isEmpty()) {
+        f.setFamily(family);
+      }
+
+      f.setWeight(OLIVE_CONFIG("DefaultSubtitleWeight").toInt());
+
       bounding_box.adjust(bounding_box.width()/10, bounding_box.height()/10, -bounding_box.width()/10, -bounding_box.height()/10);
 
-      QFont f = p.font();
-      int font_sz = bounding_box.height() / 18;
-      f.setStyleHint(QFont::SansSerif);
-      f.setFamily(f.defaultFamily());
-      f.setPointSize(font_sz);
-      f.setWeight(QFont::Bold);
-      p.setFont(f);
-      p.setPen(Qt::white);
-
-      QPainterPath path;
-
-      int text_line = 1;
+      QFontMetrics fm(f);
 
       for (int j=subtitle_tracklist.size()-1; j>=0; j--) {
         Track *sub_track = subtitle_tracklist.at(j);
         if (!sub_track->IsMuted()) {
           if (SubtitleBlock *sub = dynamic_cast<SubtitleBlock*>(sub_track->BlockAtTime(time_))) {
             // Split into lines
-            QStringList list = QtUtils::WordWrapString(sub->GetText(), p.fontMetrics(), bounding_box.width());
+            QStringList list = QtUtils::WordWrapString(sub->GetText(), fm, bounding_box.width());
 
             for (int i=list.size()-1; i>=0; i--) {
-              int w = QtUtils::QFontMetricsWidth(p.fontMetrics(), list.at(i));
-              path.addText(bounding_box.x() + bounding_box.width()/2 - w/2, bounding_box.y() + bounding_box.height() - p.fontMetrics().height() * text_line + p.fontMetrics().ascent(), p.font(), list.at(i));
-              text_line++;
+              int w = QtUtils::QFontMetricsWidth(fm, list.at(i));
+              path.addText(bounding_box.width()/2 - w/2, bounding_box.height() - fm.height() * (list.size() - i) + fm.ascent(), f, list.at(i));
             }
           }
         }
       }
 
-      p.setPen(QPen(Qt::black, font_sz / 16));
-      p.setBrush(Qt::white);
-      p.drawPath(path);
+      bool antialias = OLIVE_CONFIG("AntialiasSubtitles").toBool();
+
+      QPixmap *aa_pixmap;
+      QPainter *text_painter;
+      if (antialias) {
+        // QPainter only supports anti-aliasing in software, so to achieve it, we draw to a
+        // software buffer first and then draw that onto the hardware
+        aa_pixmap = new QPixmap(bounding_box.width(), bounding_box.height());
+        aa_pixmap->fill(Qt::transparent);
+        text_painter = new QPainter(aa_pixmap);
+      } else {
+        // Just draw straight to the hardware
+        text_painter = new QPainter(paint_device());
+
+        // Offset path by however much is necessary
+        path.translate(bounding_box.x(), bounding_box.y());
+      }
+
+      text_painter->setPen(QPen(Qt::black, f.pointSizeF() / 16));
+      text_painter->setBrush(Qt::white);
+      text_painter->setRenderHint(QPainter::Antialiasing);
+
+      text_painter->drawPath(path);
+
+      delete text_painter;
+
+      if (antialias) {
+        // We just drew to a software buffer, now draw this image onto the hardware device
+        QPainter p(paint_device());
+        p.drawPixmap(bounding_box.x(), bounding_box.y(), *aa_pixmap);
+        delete aa_pixmap;
+      }
     }
   }