tikzpreview.cpp

/***************************************************************************
 *   Copyright (C) 2007, 2008, 2009, 2010 by Glad Deschrijver              *
 *     <glad.deschrijver@gmail.com>                                        *
 *                                                                         *
 *   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 2 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 "tikzpreview.h"

#ifdef KTIKZ_USE_KDE
#include <KLocale>
#else
#include <QLocale>
#endif

#include <QApplication>
#include <QContextMenuEvent>
#include <QGraphicsPixmapItem>
#include <QGraphicsProxyWidget>
#include <QHBoxLayout>
#include <QLabel>
#include <QMenu>
#include <QScrollBar>
#include <QSettings>
#include <QToolBar>

#include <poppler-qt4.h>

#include "tikzpreviewthread.h"
#include "utils/action.h"
#include "utils/icon.h"
#include "utils/selectaction.h"
#include "utils/standardaction.h"

static const qreal s_minZoomFactor = 0.1;
static const qreal s_maxZoomFactor = 6;

TikzPreview::TikzPreview(QWidget *parent)
    : QGraphicsView(parent)
{
      m_tikzScene = new QGraphicsScene(this);
      m_tikzPixmapItem = m_tikzScene->addPixmap(QPixmap());
      setScene(m_tikzScene);
      setDragMode(QGraphicsView::ScrollHandDrag);
      setWhatsThis(tr("<p>Here the preview image of "
          "your TikZ code is shown.  You can zoom in and out, and you "
          "can scroll the image by dragging it.</p>"));

      m_tikzPdfDoc = 0;
      m_currentPage = 0;
//    m_centerPoint = QPoint(0, 0);
      m_processRunning = false;
      m_pageSeparator = 0;

      QSettings settings(ORGNAME, APPNAME);
      settings.beginGroup("Preview");
      m_zoomFactor = settings.value("ZoomFactor", 1).toDouble();
      settings.endGroup();
      m_oldZoomFactor = -1;
      m_hasZoomed = false;

      createActions();
      createInformationLabel();
      setZoomFactor(m_zoomFactor);

      m_tikzPreviewThread = new TikzPreviewThread();
      connect(m_tikzPreviewThread, SIGNAL(showPreview(QImage)), this, SLOT(showPreview(QImage)));
}

TikzPreview::~TikzPreview()
{
      delete m_infoProxyWidget;
      delete m_tikzPreviewThread;

      QSettings settings(ORGNAME, APPNAME);
      settings.beginGroup("Preview");
      settings.setValue("ZoomFactor", m_zoomFactor);
      settings.endGroup();
}

void TikzPreview::contextMenuEvent(QContextMenuEvent *event)
{
      QMenu *menu = new QMenu(this);
      menu->addActions(actions());
      menu->exec(event->globalPos());
      menu->deleteLater();
}

QSize TikzPreview::sizeHint() const
{
      return QSize(250, 200);
}

/***************************************************************************/

void TikzPreview::createActions()
{
      m_zoomInAction = StandardAction::zoomIn(this, SLOT(zoomIn()), this);
      m_zoomOutAction = StandardAction::zoomOut(this, SLOT(zoomOut()), this);
      m_zoomInAction->setStatusTip(tr("Zoom preview in"));
      m_zoomOutAction->setStatusTip(tr("Zoom preview out"));
      m_zoomInAction->setWhatsThis(tr("<p>Zoom preview in by a predetermined factor.</p>"));
      m_zoomOutAction->setWhatsThis(tr("<p>Zoom preview out by a predetermined factor.</p>"));

      m_zoomToAction = new SelectAction(Icon("zoom-original"), tr("&Zoom"), this, "zoom_to");
      m_zoomToAction->setEditable(true);
      m_zoomToAction->setToolTip(tr("Select or insert zoom factor here"));
      m_zoomToAction->setWhatsThis(tr("<p>Select the zoom factor here.  "
          "Alternatively, you can also introduce a zoom factor and "
          "press Enter.</p>"));
      connect(m_zoomToAction, SIGNAL(triggered(QString)), this, SLOT(setZoomFactor(QString)));
//    createZoomFactorList();

      m_previousPageAction = new Action(Icon("go-previous"), tr("&Previous image"), this, "view_previous_image");
      m_previousPageAction->setShortcut(tr("Alt+Left", "View|Go to previous page"));
      m_previousPageAction->setStatusTip(tr("Show previous image in preview"));
      m_previousPageAction->setWhatsThis(tr("<p>Show the preview of the previous tikzpicture in the TikZ code.</p>"));
      connect(m_previousPageAction, SIGNAL(triggered()), this, SLOT(showPreviousPage()));

      m_nextPageAction = new Action(Icon("go-next"), tr("&Next image"), this, "view_next_image");
      m_nextPageAction->setShortcut(tr("Alt+Right", "View|Go to next page"));
      m_nextPageAction->setStatusTip(tr("Show next image in preview"));
      m_nextPageAction->setWhatsThis(tr("<p>Show the preview of the next tikzpicture in the TikZ code.</p>"));
      connect(m_nextPageAction, SIGNAL(triggered()), this, SLOT(showNextPage()));

      m_previousPageAction->setVisible(false);
      m_previousPageAction->setEnabled(false);
      m_nextPageAction->setVisible(false);
      m_nextPageAction->setEnabled(true);
}

QList<QAction*> TikzPreview::actions()
{
      QList<QAction*> actions;
      actions << m_zoomInAction << m_zoomOutAction;
      QAction *action = new QAction(this);
      action->setSeparator(true);
      actions << action;
      actions << m_previousPageAction << m_nextPageAction;
      return actions;
}

QToolBar *TikzPreview::toolBar()
{
      QToolBar *viewToolBar = new QToolBar(tr("View"), this);
      viewToolBar->setObjectName("ViewToolBar");
      viewToolBar->addAction(m_zoomInAction);
      viewToolBar->addAction(m_zoomToAction);
      viewToolBar->addAction(m_zoomOutAction);
      m_pageSeparator = viewToolBar->addSeparator();
      m_pageSeparator->setVisible(false);
      viewToolBar->addAction(m_previousPageAction);
      viewToolBar->addAction(m_nextPageAction);
      return viewToolBar;
}

/***************************************************************************/

void TikzPreview::createInformationLabel()
{
#ifdef KTIKZ_USE_KDE
      const QPixmap infoPixmap = KIconLoader::global()->loadIcon("dialog-error",
          KIconLoader::Dialog, KIconLoader::SizeMedium);
#else
      const QPixmap infoPixmap = Icon("dialog-error").pixmap(QSize(32, 32));
#endif
      m_infoPixmapLabel = new QLabel;
      m_infoPixmapLabel->setPixmap(infoPixmap);

      m_infoLabel = new QLabel;

      m_infoWidget = new QFrame;
      m_infoWidget->setObjectName("infoWidget");
/*
      m_infoWidget->setStyleSheet(
          "#infoWidget {"
          "  background-color: palette(window);"
          "  border: 1px solid palette(dark);"
          "  padding: 6px;"
          "}"
      );
*/
      m_infoWidget->setFrameShape(QFrame::Box);
      m_infoWidget->setAutoFillBackground(true);

      QPalette palette = qApp->palette();
      QColor backgroundColor = palette.window().color();
      QColor foregroundColor = palette.color(QPalette::Dark);
      backgroundColor.setAlpha(150);
      foregroundColor.setAlpha(150);
      palette.setBrush(QPalette::Window, backgroundColor);
      palette.setBrush(QPalette::WindowText, foregroundColor);
      m_infoWidget->setPalette(palette);

      palette = m_infoLabel->palette();
      foregroundColor = palette.windowText().color();
      palette.setBrush(QPalette::WindowText, foregroundColor);
      m_infoLabel->setPalette(palette);

      QHBoxLayout *infoLayout = new QHBoxLayout(m_infoWidget);
      infoLayout->setMargin(10);
      infoLayout->addWidget(m_infoPixmapLabel);
      infoLayout->addWidget(m_infoLabel);

      m_infoProxyWidget = m_tikzScene->addWidget(m_infoWidget);
      m_infoProxyWidget->setZValue(1);
//    m_infoProxyWidget->setVisible(false);
      m_tikzScene->removeItem(m_infoProxyWidget);
      m_infoWidgetAdded = false;

      m_infoPixmapLabel->setVisible(false);
}

/***************************************************************************/

void TikzPreview::centerView()
{
      m_hasZoomed = true;
}

void TikzPreview::paintEvent(QPaintEvent *event)
{
      // when m_infoWidget is visible, then it must be resized and
      // repositioned, this must be done here to do it successfully
      if (m_infoWidgetAdded && m_infoWidget->isVisible())
      {
            m_infoWidget->resize(0, 0);
            centerInfoLabel();
            m_infoWidgetAdded = false;
      }

/*
      setSceneRect(m_tikzScene->itemsBoundingRect());
      if (m_hasZoomed)
      {
            // center the viewport on the same object in the image
            // that was previously the center (in order to avoid
            // flicker, this must be done here)
//          setSceneRect(m_tikzScene->itemsBoundingRect());
            if (!m_centerPoint.isNull())
                  centerOn(m_centerPoint);
            m_hasZoomed = false;
      }
*/
      if (m_hasZoomed)
      {
            // center the viewport on the same object in the image
            // that was previously the center (in order to avoid
            // flicker, this must be done here)
            const qreal zoomFraction = (m_oldZoomFactor > 0) ? m_zoomFactor / m_oldZoomFactor : 1;
            setSceneRect(m_tikzScene->itemsBoundingRect());
            centerOn((horizontalScrollBar()->value() + viewport()->width() / 2) * zoomFraction,
                (verticalScrollBar()->value() + viewport()->height() / 2) * zoomFraction);
            m_oldZoomFactor = m_zoomFactor; // m_oldZoomFactor must be set here and not in the zoom functions below in order to avoid skipping some steps when the user zooms fast
            m_hasZoomed = false;
      }
      QGraphicsView::paintEvent(event);
}

/***************************************************************************/

QString TikzPreview::formatZoomFactor(qreal zoomFactor) const
{
#ifdef KTIKZ_USE_KDE
      QString zoomFactorText = KGlobal::locale()->formatNumber(zoomFactor, 2);
      zoomFactorText.remove(KGlobal::locale()->decimalSymbol() + "00");
      // remove trailing zero in numbers like 12.30
      if (zoomFactorText.endsWith('0')
          && zoomFactorText.indexOf(KGlobal::locale()->decimalSymbol()) >= 0)
            zoomFactorText.chop(1);
      zoomFactorText += '%';
      return zoomFactorText;
#else
      return QLocale::system().toString(zoomFactor) + '%';
#endif
}

void TikzPreview::createZoomFactorList(qreal newZoomFactor)
{
      const qreal zoomFactorArray[] = {12.50, 25, 50, 75, 100, 125, 150, 200, 250, 300};
      const int zoomFactorNumber = 10;
      QStringList zoomFactorList;
      int newZoomFactorPosition = -1;
      bool addNewZoomFactor = true;

      if (newZoomFactor < s_minZoomFactor || newZoomFactor > s_maxZoomFactor)
            addNewZoomFactor = false;

      newZoomFactor *= 100;
      for (int i = 0; i < zoomFactorNumber; ++i)
      {
            if (addNewZoomFactor && newZoomFactor < zoomFactorArray[i])
            {
                  zoomFactorList << formatZoomFactor(newZoomFactor);
                  newZoomFactorPosition = i;
                  addNewZoomFactor = false;
            }
            else if (newZoomFactor == zoomFactorArray[i])
            {
                  newZoomFactorPosition = i;
                  addNewZoomFactor = false;
            }
            zoomFactorList << formatZoomFactor(zoomFactorArray[i]);
      }
      if (addNewZoomFactor)
      {
            zoomFactorList << formatZoomFactor(newZoomFactor);
            newZoomFactorPosition = zoomFactorNumber;
      }

      disconnect(m_zoomToAction, SIGNAL(triggered(QString)), this, SLOT(setZoomFactor(QString)));
      m_zoomToAction->removeAllActions();
      m_zoomToAction->setItems(zoomFactorList);
      if (newZoomFactorPosition >= 0)
            m_zoomToAction->setCurrentItem(newZoomFactorPosition);
      connect(m_zoomToAction, SIGNAL(triggered(QString)), this, SLOT(setZoomFactor(QString)));
}

/***************************************************************************/

void TikzPreview::setZoomFactor(qreal zoomFactor)
{
//    m_oldZoomFactor = m_zoomFactor;
      m_zoomFactor = zoomFactor;
      if (m_zoomFactor == m_oldZoomFactor)
            return;

      // adjust zoom factor
      m_zoomFactor = qBound(s_minZoomFactor, m_zoomFactor, s_maxZoomFactor);

      // add current zoom factor to the list of zoom factors
      const QString zoomFactorString = formatZoomFactor(m_zoomFactor * 100);
      const int zoomFactorIndex = m_zoomToAction->items().indexOf(zoomFactorString);
      if (zoomFactorIndex >= 0)
            m_zoomToAction->setCurrentItem(zoomFactorIndex);
      else
            createZoomFactorList(m_zoomFactor);

      m_zoomInAction->setEnabled(m_zoomFactor < s_maxZoomFactor);
      m_zoomOutAction->setEnabled(m_zoomFactor > s_minZoomFactor);

      showPdfPage();
}

void TikzPreview::setZoomFactor(const QString &zoomFactorText)
{
#ifdef KTIKZ_USE_KDE
      setZoomFactor(KGlobal::locale()->readNumber(QString(zoomFactorText).remove('&').remove('%')) / 100.0);
#else
      setZoomFactor(QString(zoomFactorText).remove(QRegExp(QString("[^\\d\\%1]*").arg(QLocale::system().decimalPoint()))).toDouble() / 100);
#endif
}

void TikzPreview::zoomIn()
{
      setZoomFactor(m_zoomFactor + ((m_zoomFactor > 0.99) ?
          (m_zoomFactor > 1.99 ? 0.5 : 0.2) : 0.1));
}

void TikzPreview::zoomOut()
{
      setZoomFactor(m_zoomFactor - ((m_zoomFactor > 1.01) ?
          (m_zoomFactor > 2.01 ? 0.5 : 0.2) : 0.1));
}

/***************************************************************************/

void TikzPreview::showPreviousPage()
{
      if (m_currentPage > 0)
            --m_currentPage;
      m_previousPageAction->setEnabled(m_currentPage > 0);
      m_nextPageAction->setEnabled(m_currentPage < m_tikzPdfDoc->numPages() - 1);
      showPdfPage();
}

void TikzPreview::showNextPage()
{
      if (m_currentPage < m_tikzPdfDoc->numPages() - 1)
            ++m_currentPage;
      m_previousPageAction->setEnabled(m_currentPage > 0);
      m_nextPageAction->setEnabled(m_currentPage < m_tikzPdfDoc->numPages() - 1);
      showPdfPage();
}

void TikzPreview::showPreview(const QImage &tikzImage)
{
      m_tikzPixmapItem->setPixmap(QPixmap::fromImage(tikzImage));
      m_tikzPixmapItem->update();
      centerView(); // adjust viewport when new objects are added to the tikz picture or when zooming
}

void TikzPreview::showPdfPage()
{
      if (!m_tikzPdfDoc || m_tikzPdfDoc->numPages() < 1)
            return;

//    m_centerPoint = QPoint(horizontalScrollBar()->value() + viewport()->width() / 2,
//        verticalScrollBar()->value() + viewport()->height() / 2); // get current center of the viewport and use it in paintEvent

      if (!m_processRunning)
            m_tikzPreviewThread->generatePreview(m_tikzPdfDoc, m_zoomFactor, m_currentPage);
/*
      if (!m_processRunning)
      {
            Poppler::Page *pdfPage = m_tikzPdfDoc->page(m_currentPage);
            m_tikzPixmapItem->setPixmap(QPixmap::fromImage(pdfPage->renderToImage(m_zoomFactor * 72, m_zoomFactor * 72)));
            m_tikzPixmapItem->update();
            centerView(); // adjust viewport when new objects are added to the tikz picture
            delete pdfPage;
      }
*/
}

void TikzPreview::emptyPreview()
{
      m_tikzPdfDoc = 0;
      m_tikzPixmapItem->setPixmap(QPixmap());
      m_tikzPixmapItem->update();
//    m_infoWidget->setVisible(false);
      if (m_infoProxyWidget->scene() != 0) // remove error messages from view
            m_tikzScene->removeItem(m_infoProxyWidget);
      m_tikzScene->setSceneRect(0, 0, 1, 1); // remove scrollbars from view
      if (m_pageSeparator)
            m_pageSeparator->setVisible(false);
      m_previousPageAction->setVisible(false);
      m_nextPageAction->setVisible(false);
}

void TikzPreview::pixmapUpdated(Poppler::Document *tikzPdfDoc)
{
      m_tikzPdfDoc = tikzPdfDoc;

    if (!m_tikzPdfDoc)
      {
            emptyPreview();
            return;
      }

      m_tikzPdfDoc->setRenderBackend(Poppler::Document::SplashBackend);
//    m_tikzPdfDoc->setRenderBackend(Poppler::Document::ArthurBackend);
      m_tikzPdfDoc->setRenderHint(Poppler::Document::Antialiasing, true);
      m_tikzPdfDoc->setRenderHint(Poppler::Document::TextAntialiasing, true);
      const int numOfPages = m_tikzPdfDoc->numPages();

      const bool visible = (numOfPages > 1);
      if (m_pageSeparator)
            m_pageSeparator->setVisible(visible);
      m_previousPageAction->setVisible(visible);
      m_nextPageAction->setVisible(visible);

      if (m_currentPage >= numOfPages) // if the new tikz code has fewer tikzpictures than the previous one (this may happen if a new PGF file is opened in the same window), then we must reset m_currentPage
      {
            m_currentPage = 0;
            m_previousPageAction->setEnabled(false);
            m_nextPageAction->setEnabled(true);
      }

      showPdfPage();
}

/***************************************************************************/

QPixmap TikzPreview::pixmap() const
{
      return m_tikzPixmapItem->pixmap();
}

/***************************************************************************/

void TikzPreview::centerInfoLabel()
{
      qreal posX = (sceneRect().width() - m_infoWidget->width()) / 2;
      qreal posY = (sceneRect().height() - m_infoWidget->height()) / 2;

      if (sceneRect().width() > viewport()->width())
            posX += horizontalScrollBar()->value();
      if (sceneRect().height() > viewport()->height())
            posY += verticalScrollBar()->value();

      m_infoWidget->move(posX, posY);
}

void TikzPreview::setInfoLabelText(const QString &message, bool isPixmapVisible)
{
      m_infoPixmapLabel->setVisible(isPixmapVisible);
      m_infoLabel->setText(message);
//    m_infoWidget->setVisible(false);
//    m_infoWidget->setVisible(true);
      if (m_infoProxyWidget->scene() != 0) // only remove if the widget is still attached to m_tikzScene
            m_tikzScene->removeItem(m_infoProxyWidget); // make sure that any previous messages are not visible anymore
      m_tikzScene->addItem(m_infoProxyWidget);
      m_infoWidgetAdded = true;
}

void TikzPreview::showErrorMessage(const QString &message)
{
      setInfoLabelText(message, true);
}

void TikzPreview::setProcessRunning(bool isRunning)
{
      m_processRunning = isRunning;
      if (isRunning)
            setInfoLabelText(tr("Generating image", "tikz preview status"), false);
//    else
//          m_infoWidget->setVisible(false);
      else if (m_infoProxyWidget->scene() != 0) // only remove if the widget is still attached to m_tikzScene
            m_tikzScene->removeItem(m_infoProxyWidget);
}

/***************************************************************************/

void TikzPreview::wheelEvent(QWheelEvent *event)
{
      if (event->modifiers() == Qt::ControlModifier)
      {
            if (event->delta() > 0)
                  zoomIn();
            else
                  zoomOut();
      }
      else
            QGraphicsView::wheelEvent(event);
}