message preview refactor, several bugs about label size, animations are now playing in previews

ui/widgets/messageline/preview.cpp

@@ -0,0 +1,304 @@
+/*
+ * Squawk messenger. 
+ * Copyright (C) 2019  Yury Gubich <blue@macaw.me>
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "preview.h"
+
+
+constexpr int margin = 6;
+constexpr int maxAttachmentHeight = 500;
+
+bool Preview::fontInitialized = false;
+QFont Preview::font;
+QFontMetrics Preview::metrics(Preview::font);
+
+Preview::Preview(const QString& pPath, const QSize& pMaxSize, const QPoint& pos, bool pRight, QWidget* pParent):
+    info(Shared::Global::getFileInfo(pPath)),
+    path(pPath),
+    maxSize(pMaxSize),
+    actualSize(constrainAttachSize(info.size, maxSize)),
+    cachedLabelSize(0, 0),
+    position(pos),
+    widget(0),
+    label(0),
+    parent(pParent),
+    movie(0),
+    fileReachable(true),
+    actualPreview(false),
+    right(pRight)
+{
+    if (!fontInitialized) {
+        font.setBold(true);
+        font.setPixelSize(14);
+        metrics = QFontMetrics(font);
+        fontInitialized = true;
+    }
+    
+    initializeElements();
+    if (fileReachable) {
+        positionElements();
+    }
+}
+
+Preview::~Preview()
+{
+    clean();
+}
+
+void Preview::clean()
+{
+    if (fileReachable) {
+        if (info.preview == Shared::Global::FileInfo::Preview::animation) {
+            delete movie;
+        }
+        delete widget;
+        if (!actualPreview) {
+            delete label;
+        } else {
+            actualPreview = false;
+        }
+    } else {
+        fileReachable = true;
+    }
+}
+
+void Preview::actualize(const QString& newPath, const QSize& newSize, const QPoint& newPoint)
+{
+    bool positionChanged = false;
+    bool sizeChanged = false;
+    bool maxSizeChanged = false;
+    
+    if (maxSize != newSize) {
+        maxSize = newSize;
+        maxSizeChanged = true;
+        QSize ns = constrainAttachSize(info.size, maxSize);
+        if (actualSize != ns) {
+            sizeChanged = true;
+            actualSize = ns;
+        }
+    }
+    if (position != newPoint) {
+        position = newPoint;
+        positionChanged = true;
+    }
+    
+    if (!setPath(newPath) && fileReachable) {
+        if (sizeChanged) {
+            applyNewSize();
+            if (maxSizeChanged && !actualPreview) {
+                applyNewMaxSize();
+            }
+        } else if (maxSizeChanged) {
+            applyNewMaxSize();
+        }
+        if (positionChanged || !actualPreview) {
+            positionElements();
+        }
+    }
+}
+
+void Preview::setSize(const QSize& newSize)
+{
+    bool sizeChanged = false;
+    bool maxSizeChanged = false;
+    
+    if (maxSize != newSize) {
+        maxSize = newSize;
+        maxSizeChanged = true;
+        QSize ns = constrainAttachSize(info.size, maxSize);
+        if (actualSize != ns) {
+            sizeChanged = true;
+            actualSize = ns;
+        }
+    }
+    
+    if (fileReachable) {
+        if (sizeChanged) {
+            applyNewSize();
+        }
+        if (maxSizeChanged || !actualPreview) {
+            applyNewMaxSize();
+        }
+    }
+}
+
+void Preview::applyNewSize()
+{
+    switch (info.preview) {
+        case Shared::Global::FileInfo::Preview::picture: {
+            QPixmap img(path);
+            if (img.isNull()) {
+                fileReachable = false;
+            } else {
+                img = img.scaled(actualSize, Qt::KeepAspectRatio);
+                widget->resize(actualSize);
+                widget->setPixmap(img);
+            }
+        }
+            break;
+        case Shared::Global::FileInfo::Preview::animation:{
+            movie->setScaledSize(actualSize);
+            widget->resize(actualSize);
+        }
+            break;
+        default: {
+            QIcon icon = QIcon::fromTheme(info.mime.iconName());
+            widget->setPixmap(icon.pixmap(actualSize));
+            widget->resize(actualSize);
+        }
+    }
+}
+
+void Preview::applyNewMaxSize()
+{
+    switch (info.preview) {
+        case Shared::Global::FileInfo::Preview::picture: 
+        case Shared::Global::FileInfo::Preview::animation: 
+            break;
+        default: {
+            int labelWidth = maxSize.width() - actualSize.width() - margin;
+            QString elidedName = metrics.elidedText(info.name, Qt::ElideMiddle, labelWidth);
+            cachedLabelSize = metrics.size(0, elidedName);
+            label->setText(elidedName);
+            label->resize(cachedLabelSize);
+        }
+    }
+}
+
+
+QSize Preview::size() const
+{
+    if (actualPreview) {
+        return actualSize;
+    } else {
+        return QSize(actualSize.width() + margin + cachedLabelSize.width(), actualSize.height());
+    }
+}
+
+bool Preview::isFileReachable() const
+{
+    return fileReachable;
+}
+
+void Preview::setPosition(const QPoint& newPoint)
+{
+    if (position != newPoint) {
+        position = newPoint;
+        if (fileReachable) {
+            positionElements();
+        }
+    }
+}
+
+bool Preview::setPath(const QString& newPath)
+{
+    if (path != newPath) {
+        path = newPath;
+        info = Shared::Global::getFileInfo(path);
+        actualSize = constrainAttachSize(info.size, maxSize);
+        clean();
+        initializeElements();
+        if (fileReachable) {
+            positionElements();
+        }
+        return true;
+    } else {
+        return false;
+    }
+}
+
+void Preview::initializeElements()
+{
+    switch (info.preview) {
+        case Shared::Global::FileInfo::Preview::picture: {
+            QPixmap img(path);
+            if (img.isNull()) {
+                fileReachable = false;
+            } else {
+                actualPreview = true;
+                img = img.scaled(actualSize, Qt::KeepAspectRatio);
+                widget = new QLabel(parent);
+                widget->setPixmap(img);
+                widget->show();
+            }
+        }
+            break;
+        case Shared::Global::FileInfo::Preview::animation:{
+            movie = new QMovie(path);
+            if (!movie->isValid()) {
+                fileReachable = false;
+                delete movie;
+            } else {
+                actualPreview = true;
+                movie->setScaledSize(actualSize);
+                widget = new QLabel(parent);
+                widget->setMovie(movie);
+                movie->start();
+                widget->show();
+            }
+        }
+            break;
+        default: {
+            QIcon icon = QIcon::fromTheme(info.mime.iconName());
+            widget = new QLabel(parent);
+            widget->setPixmap(icon.pixmap(actualSize));
+            widget->show();
+            
+            label = new QLabel(parent);
+            label->setFont(font);
+            int labelWidth = maxSize.width() - actualSize.width() - margin;
+            QString elidedName = metrics.elidedText(info.name, Qt::ElideMiddle, labelWidth);
+            cachedLabelSize = metrics.size(0, elidedName);
+            label->setText(elidedName);
+            label->show();
+        }
+    }
+}
+
+void Preview::positionElements()
+{
+    int start = position.x();
+    if (right) {
+        start += maxSize.width() - size().width();
+    }
+    widget->move(start, position.y());
+    if (!actualPreview) {
+        int x = start + actualSize.width() + margin;
+        int y = position.y() + (actualSize.height() - cachedLabelSize.height()) / 2;
+        label->move(x, y);
+    }
+}
+
+QSize Preview::calculateAttachSize(const QString& path, const QRect& bounds)
+{
+    Shared::Global::FileInfo info = Shared::Global::getFileInfo(path);
+    
+    return constrainAttachSize(info.size, bounds.size());
+}
+
+QSize Preview::constrainAttachSize(QSize src, QSize bounds)
+{
+    if (bounds.height() > maxAttachmentHeight) {
+        bounds.setHeight(maxAttachmentHeight);
+    }
+    
+    if (src.width() > bounds.width() || src.height() > bounds.height()) {
+        src.scale(bounds, Qt::KeepAspectRatio);
+    }
+    
+    return src;
+}