an attempt to display text in a better way with QTextDocument + QTextBrowser

shared/utils.cpp

@@ -40,5 +40,5 @@ QString Shared::processMessageBody(const QString& msg)
 {
     QString processed = msg.toHtmlEscaped();
     processed.replace(urlReg, "<a href=\"\\1\">\\1</a>");
-    return "<p style=\"white-space: pre-wrap;\">" + processed + "</p>";
+    return "<p style=\"white-space: pre-wrap; line-height: 1em;\">" + processed + "</p>";
 }

ui/utils/CMakeLists.txt

@@ -15,6 +15,4 @@ target_sources(squawk PRIVATE
   resizer.h
   shadowoverlay.cpp
   shadowoverlay.h
-  textmeter.cpp
-  textmeter.h
   )

ui/utils/textmeter.cpp

@@ -1,233 +0,0 @@
-// 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 "textmeter.h"
-#include <QDebug>
-#include <QApplication>
-
-TextMeter::TextMeter():
-    base(),
-    fonts()
-{
-}
-
-TextMeter::~TextMeter()
-{
-}
-
-void TextMeter::initializeFonts(const QFont& font)
-{
-    fonts.clear();
-    QList<QFontDatabase::WritingSystem> supported = base.writingSystems(font.family());
-    std::set<QFontDatabase::WritingSystem> sup;
-    std::set<QString> added({font.family()});
-    for (const QFontDatabase::WritingSystem& system : supported) {
-        sup.insert(system);
-    }
-    fonts.push_back(QFontMetrics(font));
-    QString style = base.styleString(font);
-
-    QList<QFontDatabase::WritingSystem> systems = base.writingSystems();
-    for (const QFontDatabase::WritingSystem& system : systems) {
-        if (sup.count(system) == 0) {
-            QStringList families = base.families(system);
-            if (!families.empty() && added.count(families.first()) == 0) {
-                QString family(families.first());
-                QFont nfont = base.font(family, style, font.pointSize());
-                if (added.count(nfont.family()) == 0) {
-                    added.insert(family);
-                    fonts.push_back(QFontMetrics(nfont));
-                    qDebug() << "Added font" << nfont.family() << "for" << system;
-                }
-            }
-        }
-    }
-}
-
-QSize TextMeter::boundingSize(const QString& text, const QSize& limits) const
-{
-//     QString str("ridiculus mus. Suspendisse potenti. Cras pretium venenatis enim, faucibus accumsan ex");
-//     bool first = true;
-//     int width = 0;
-//     QStringList list = str.split(" ");
-//     QFontMetrics m = fonts.front();
-//     for (const QString& word : list) {
-//         if (first) {
-//             first = false;
-//         } else {
-//             width += m.horizontalAdvance(QChar::Space);
-//         }
-//         width += m.horizontalAdvance(word);
-//         for (const QChar& ch : word) {
-//             width += m.horizontalAdvance(ch);
-//         }
-//     }
-//     qDebug() << "together:" << m.horizontalAdvance(str);
-//     qDebug() << "apart:" << width;
-//     I cant measure or wrap text this way, this simple example shows that even this gives differen result
-//     The Qt implementation under it is thousands and thousands lines of code in QTextEngine
-//     I simply can't get though it
-
-    if (text.size() == 0) {
-        return QSize (0, 0);
-    }
-    Helper current(limits.width());
-    for (const QChar& ch : text) {
-        if (newLine(ch)) {
-            current.computeNewWord();
-            if (current.height == 0) {
-                current.height = fonts.front().lineSpacing();
-            }
-            current.beginNewLine();
-        } else if (visible(ch)) {
-            bool found = false;
-            for (const QFontMetrics& metrics : fonts) {
-                if (metrics.inFont(ch)) {
-                    current.computeChar(ch, metrics);
-                    found = true;
-                    break;
-                }
-            }
-
-            if (!found) {
-                current.computeChar(ch, fonts.front());
-            }
-        }
-    }
-    current.computeNewWord();
-    current.beginNewLine();
-
-    int& height = current.size.rheight();
-    if (height > 0) {
-        height -= fonts.front().leading();
-    }
-
-    return current.size;
-}
-
-void TextMeter::Helper::computeChar(const QChar& ch, const QFontMetrics& metrics)
-{
-    int ha = metrics.horizontalAdvance(ch);
-    if (newWord(ch)) {
-        if (printOnLineBreak(ch)) {
-            if (!lineOverflow(metrics, ha, ch)){
-                computeNewWord();
-            }
-        } else {
-            computeNewWord();
-            delayedSpaceWidth = ha;
-            lastSpace = ch;
-        }
-    } else {
-        lineOverflow(metrics, ha, ch);
-    }
-}
-
-void TextMeter::Helper::computeNewLine(const QFontMetrics& metrics, int horizontalAdvance, const QChar& ch)
-{
-    if (wordBeganWithTheLine) {
-        text = word.chopped(1);
-        width = wordWidth - horizontalAdvance;
-        height = wordHeight;
-    }
-    if (width != metrics.horizontalAdvance(text)) {
-        qDebug() << "Kerning Error" << width - metrics.horizontalAdvance(text);
-    }
-    beginNewLine();
-    if (wordBeganWithTheLine) {
-        word = ch;
-        wordWidth = horizontalAdvance;
-        wordHeight = metrics.lineSpacing();
-    }
-
-    wordBeganWithTheLine = true;
-    delayedSpaceWidth = 0;
-    lastSpace = QChar::Null;
-}
-
-void TextMeter::Helper::beginNewLine()
-{
-    size.rheight() += height;
-    size.rwidth() = qMax(size.width(), width);
-    qDebug() << text;
-    text = "";
-    width = 0;
-    height = 0;
-}
-
-void TextMeter::Helper::computeNewWord()
-{
-    width += wordWidth + delayedSpaceWidth;
-    height = qMax(height, wordHeight);
-    if (lastSpace != QChar::Null) {
-        text += lastSpace;
-    }
-    text += word;
-    word = "";
-    wordWidth = 0;
-    wordHeight = 0;
-    delayedSpaceWidth = 0;
-    lastSpace = QChar::Null;
-    wordBeganWithTheLine = false;
-}
-
-bool TextMeter::Helper::lineOverflow(const QFontMetrics& metrics, int horizontalAdvance, const QChar& ch)
-{
-    wordHeight = qMax(wordHeight, metrics.lineSpacing());
-    wordWidth += horizontalAdvance;
-    word += ch;
-    if (width + delayedSpaceWidth + wordWidth > maxWidth) {
-        computeNewLine(metrics, horizontalAdvance, ch);
-        return true;
-    }
-    return false;
-}
-
-
-bool TextMeter::newLine(const QChar& ch)
-{
-    return ch == QChar::LineFeed;
-}
-
-bool TextMeter::newWord(const QChar& ch)
-{
-    return ch.isSpace() || ch.isPunct();
-}
-
-bool TextMeter::printOnLineBreak(const QChar& ch)
-{
-    return ch != QChar::Space;
-}
-
-bool TextMeter::visible(const QChar& ch)
-{
-    return true;
-}
-
-TextMeter::Helper::Helper(int p_maxWidth):
-    width(0),
-    height(0),
-    wordWidth(0),
-    wordHeight(0),
-    delayedSpaceWidth(0),
-    maxWidth(p_maxWidth),
-    wordBeganWithTheLine(true),
-    text(""),
-    word(""),
-    lastSpace(QChar::Null),
-    size(0, 0)
-{
-}

ui/utils/textmeter.h

@@ -1,68 +0,0 @@
-// 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/>.
-
-#ifndef TEXTMETER_H
-#define TEXTMETER_H
-
-#include <list>
-#include <set>
-
-#include <QFontMetrics>
-#include <QFont>
-#include <QSize>
-#include <QFontDatabase>
-
-class TextMeter
-{
-public:
-    TextMeter();
-    ~TextMeter();
-    void initializeFonts(const QFont& font);
-    QSize boundingSize(const QString& text, const QSize& limits) const;
-
-private:
-    QFontDatabase base;
-    std::list<QFontMetrics> fonts;
-
-    struct Helper {
-        Helper(int maxWidth);
-        int width;
-        int height;
-        int wordWidth;
-        int wordHeight;
-        int delayedSpaceWidth;
-        int maxWidth;
-        bool wordBeganWithTheLine;
-        QString text;
-        QString word;
-        QChar lastSpace;
-        QSize size;
-
-        void computeNewLine(const QFontMetrics& metrics, int horizontalAdvance, const QChar& ch);
-        void computeChar(const QChar& ch, const QFontMetrics& metrics);
-        void computeNewWord();
-        void beginNewLine();
-        bool lineOverflow(const QFontMetrics& metrics, int horizontalAdvance, const QChar& ch);
-    };
-
-    static bool newLine(const QChar& ch);
-    static bool newWord(const QChar& ch);
-    static bool visible(const QChar& ch);
-    static bool printOnLineBreak(const QChar& ch);
-
-};
-
-#endif // TEXTMETER_H

ui/widgets/messageline/feedview.cpp

@@ -343,6 +343,7 @@ void FeedView::paintEvent(QPaintEvent* event)
     
     QDateTime lastDate;
     bool first = true;
+    QRect viewportRect = vp->rect();
     for (const QModelIndex& index : toRener) {
         QDateTime currentDate = index.data(Models::MessageFeed::Date).toDateTime();
         option.rect = visualRect(index);
@@ -356,7 +357,10 @@ void FeedView::paintEvent(QPaintEvent* event)
             }
             first = false;
         }
-        bool mouseOver = option.rect.contains(cursor) && vp->rect().contains(cursor);
+        QRect stripe = option.rect;
+        stripe.setLeft(0);
+        stripe.setWidth(viewportRect.width());
+        bool mouseOver = stripe.contains(cursor) && viewportRect.contains(cursor);
         option.state.setFlag(QStyle::State_MouseOver, mouseOver);
         itemDelegate(index)->paint(&painter, option, index);
 

ui/widgets/messageline/messagedelegate.cpp

@@ -22,6 +22,7 @@
 #include <QApplication>
 #include <QMouseEvent>
 #include <QAbstractItemView>
+#include <QtMath>
 
 #include "messagedelegate.h"
 #include "messagefeed.h"
@@ -42,7 +43,7 @@ MessageDelegate::MessageDelegate(QObject* parent):
     nickFont(),
     dateFont(),
     bodyMetrics(bodyFont),
-    bodyMeter(),
+    bodyRenderer(new QTextDocument()),
     nickMetrics(nickFont),
     dateMetrics(dateFont),
     buttonHeight(0),
@@ -52,11 +53,13 @@ MessageDelegate::MessageDelegate(QObject* parent):
     bars(new std::map<QString, QProgressBar*>()),
     statusIcons(new std::map<QString, QLabel*>()),
     pencilIcons(new std::map<QString, QLabel*>()),
-    bodies(new std::map<QString, QLabel*>()),
+    bodies(new std::map<QString, QTextBrowser*>()),
     previews(new std::map<QString, Preview*>()),
     idsToKeep(new std::set<QString>()),
     clearingWidgets(false)
 {
+    bodyRenderer->setDocumentMargin(0);
+
     QPushButton btn(QCoreApplication::translate("MessageLine", "Download"));
     buttonHeight = btn.sizeHint().height();
     buttonWidth = btn.sizeHint().width();
@@ -83,7 +86,7 @@ MessageDelegate::~MessageDelegate()
         delete pair.second;
     }
     
-    for (const std::pair<const QString, QLabel*>& pair: *bodies){
+    for (const std::pair<const QString, QTextBrowser*>& pair: *bodies){
         delete pair.second;
     }
     
@@ -98,6 +101,7 @@ MessageDelegate::~MessageDelegate()
     delete bars;
     delete bodies;
     delete previews;
+    delete bodyRenderer;
 }
 
 void MessageDelegate::paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const
@@ -124,8 +128,6 @@ void MessageDelegate::paint(QPainter* painter, const QStyleOptionViewItem& optio
         opt.displayAlignment = Qt::AlignRight | Qt::AlignTop;
     }
 
-    QSize bodySize = bodyMeter.boundingSize(data.text, opt.rect.size());
-
     QRect rect;
     if (ntds) {
         painter->setFont(nickFont);
@@ -168,15 +170,7 @@ void MessageDelegate::paint(QPainter* painter, const QStyleOptionViewItem& optio
     painter->restore();
     
     QWidget* vp = static_cast<QWidget*>(painter->device());
-    if (data.text.size() > 0) {
+    paintBody(data, painter, opt);
-        QLabel* body = getBody(data);
-        body->setParent(vp);
-        body->setMinimumSize(bodySize);
-        body->setMaximumSize(bodySize);
-        body->move(opt.rect.left(), opt.rect.y());
-        body->show();
-        opt.rect.adjust(0, bodySize.height() + textMargin, 0, 0);
-    }
     painter->setFont(dateFont);
     QColor q = painter->pen().color();
     QString dateString = data.date.toLocalTime().toString("hh:mm");
@@ -304,7 +298,12 @@ QSize MessageDelegate::sizeHint(const QStyleOptionViewItem& option, const QModel
     Models::FeedItem data = qvariant_cast<Models::FeedItem>(vi);
     QSize messageSize(0, 0);
     if (data.text.size() > 0) {
-        messageSize = bodyMeter.boundingSize(data.text, messageRect.size());
+        bodyRenderer->setPlainText(data.text);
+        bodyRenderer->setTextWidth(messageRect.size().width());
+
+        QSizeF size = bodyRenderer->size();
+        size.setWidth(bodyRenderer->idealWidth());
+        messageSize = QSize(qCeil(size.width()), qCeil(size.height()));
         messageSize.rheight() += textMargin;
     }
     
@@ -393,7 +392,7 @@ void MessageDelegate::initializeFonts(const QFont& font)
     nickMetrics = QFontMetrics(nickFont);
     dateMetrics = QFontMetrics(dateFont);
 
-    bodyMeter.initializeFonts(bodyFont);
+    bodyRenderer->setDefaultFont(bodyFont);
     
     Preview::initializeFont(bodyFont);
 }
@@ -573,34 +572,36 @@ QLabel * MessageDelegate::getPencilIcon(const Models::FeedItem& data) const
     return result;
 }
 
-QLabel * MessageDelegate::getBody(const Models::FeedItem& data) const
+QTextBrowser * MessageDelegate::getBody(const Models::FeedItem& data) const
 {
-    std::map<QString, QLabel*>::const_iterator itr = bodies->find(data.id);
+    std::map<QString, QTextBrowser*>::const_iterator itr = bodies->find(data.id);
-    QLabel* result = 0;
+    QTextBrowser* result = 0;
     
     if (itr != bodies->end()) {
         result = itr->second;
     } else {
-        result = new QLabel();
+        result = new QTextBrowser();
         result->setFont(bodyFont);
         result->setContextMenuPolicy(Qt::NoContextMenu);
-        result->setWordWrap(true);
+        result->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+        result->setContentsMargins(0, 0, 0, 0);
+        //result->viewport()->setAutoFillBackground(false);
+        result->document()->setDocumentMargin(0);
+        result->setFrameStyle(0);
+        result->setLineWidth(0);
+        //result->setAutoFillBackground(false);
+        //->setWordWrap(true);
+        result->setOpenExternalLinks(true);
+        //result->setTextInteractionFlags(result->textInteractionFlags() | Qt::TextSelectableByMouse | Qt::LinksAccessibleByMouse);
         result->setOpenExternalLinks(true);
-        result->setTextInteractionFlags(result->textInteractionFlags() | Qt::TextSelectableByMouse | Qt::LinksAccessibleByMouse);
         bodies->insert(std::make_pair(data.id, result));
     }
     
-    result->setText(Shared::processMessageBody(data.text));
+    result->setHtml(Shared::processMessageBody(data.text));
     
     return result;
 }
 
-void MessageDelegate::beginClearWidgets()
-{
-    idsToKeep->clear();
-    clearingWidgets = true;
-}
-
 template <typename T>
 void removeElements(std::map<QString, T*>* elements, std::set<QString>* idsToKeep) {
     std::set<QString> toRemove;
@@ -615,6 +616,51 @@ void removeElements(std::map<QString, T*>* elements, std::set<QString>* idsToKee
     }
 }
 
+int MessageDelegate::paintBody(const Models::FeedItem& data, QPainter* painter, QStyleOptionViewItem& option) const
+{
+    if (data.text.size() > 0) {
+        bodyRenderer->setHtml(Shared::processMessageBody(data.text));
+        bodyRenderer->setTextWidth(option.rect.size().width());
+        painter->save();
+        painter->translate(option.rect.topLeft());
+        bodyRenderer->drawContents(painter);
+        painter->restore();
+        QSize bodySize(qCeil(bodyRenderer->idealWidth()), qCeil(bodyRenderer->size().height()));
+
+
+        QTextBrowser* editor = nullptr;
+        if (option.state.testFlag(QStyle::State_MouseOver)) {
+            std::set<QString> ids({data.id});
+            removeElements(bodies, &ids);
+            editor = getBody(data);
+            editor->setParent(static_cast<QWidget*>(painter->device()));
+        } else {
+            std::map<QString, QTextBrowser*>::const_iterator itr = bodies->find(data.id);
+            if (itr != bodies->end()) {
+                editor = itr->second;
+            }
+        }
+        if (editor != nullptr) {
+            editor->setMinimumSize(bodySize);
+            editor->setMaximumSize(bodySize);
+            editor->move(option.rect.left(), option.rect.y());
+            editor->show();
+        }
+
+        option.rect.adjust(0, bodySize.height() + textMargin, 0, 0);
+        return bodySize.width();
+    }
+    return 0;
+}
+
+void MessageDelegate::beginClearWidgets()
+{
+    idsToKeep->clear();
+    clearingWidgets = true;
+}
+
+
+
 void MessageDelegate::endClearWidgets()
 {
     if (clearingWidgets) {

ui/widgets/messageline/messagedelegate.h

@@ -29,12 +29,13 @@
 #include <QPushButton>
 #include <QProgressBar>
 #include <QLabel>
+#include <QTextEdit>
+#include <QTextBrowser>
 
 #include "shared/icons.h"
 #include "shared/global.h"
 #include "shared/utils.h"
 #include "shared/pathcheck.h"
-#include "ui/utils/textmeter.h"
 
 #include "preview.h"
 
@@ -70,13 +71,15 @@ protected:
     int paintBar(QProgressBar* bar, QPainter* painter, bool sentByMe, QStyleOptionViewItem& option) const;
     int paintPreview(const Models::FeedItem& data, QPainter* painter, QStyleOptionViewItem& option) const;
     int paintComment(const Models::FeedItem& data, QPainter* painter, QStyleOptionViewItem& option) const;
+    int paintBody(const Models::FeedItem& data, QPainter* painter, QStyleOptionViewItem& option) const;
     void paintAvatar(const Models::FeedItem& data, const QModelIndex& index, const QStyleOptionViewItem& option, QPainter* painter) const;
     void paintBubble(const Models::FeedItem& data, QPainter* painter, const QStyleOptionViewItem& option) const;
+
     QPushButton* getButton(const Models::FeedItem& data) const;
     QProgressBar* getBar(const Models::FeedItem& data) const;
     QLabel* getStatusIcon(const Models::FeedItem& data) const;
     QLabel* getPencilIcon(const Models::FeedItem& data) const;
-    QLabel* getBody(const Models::FeedItem& data) const;
+    QTextBrowser* getBody(const Models::FeedItem& data) const;
     void clearHelperWidget(const Models::FeedItem& data) const;
 
     bool needToDrawAvatar(const QModelIndex& index, const Models::FeedItem& data, const QStyleOptionViewItem& option) const;
@@ -95,7 +98,7 @@ private:
     QFont nickFont;
     QFont dateFont;
     QFontMetrics bodyMetrics;
-    TextMeter bodyMeter;
+    QTextDocument* bodyRenderer;
     QFontMetrics nickMetrics;
     QFontMetrics dateMetrics;
     
@@ -107,7 +110,7 @@ private:
     std::map<QString, QProgressBar*>* bars;
     std::map<QString, QLabel*>* statusIcons;
     std::map<QString, QLabel*>* pencilIcons;
-    std::map<QString, QLabel*>* bodies;
+    std::map<QString, QTextBrowser*>* bodies;
     std::map<QString, Preview*>* previews;
     std::set<QString>* idsToKeep;
     bool clearingWidgets;