File indexing completed on 2024-05-19 05:28:18

 /*
     SPDX-FileCopyrightText: 2007 Robert Knight <robertknight@gmail.com>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 
     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, write to the Free Software
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
     02110-1301  USA.
 */
 
 // Own
 #include "ScreenWindow.h"
 
 // Qt
 #include <QtDebug>
 
 // Konsole
 #include "Screen.h"
 
 using namespace Konsole;
 
 ScreenWindow::ScreenWindow(QObject *parent)
     : QObject(parent)
     , _screen(nullptr)
     , _windowBufferSize(0)
     , _bufferNeedsUpdate(true)
     , _windowLines(1)
     , _currentLine(0)
     , _trackOutput(true)
     , _scrollCount(0)
 {
 }
 ScreenWindow::~ScreenWindow() = default;
 
 void ScreenWindow::setScreen(Screen *screen)
 {
     Q_ASSERT(screen);
 
     _screen = screen;
 }
 
 Screen *ScreenWindow::screen() const
 {
     return _screen;
 }
 
 std::span<Character> ScreenWindow::getImage()
 {
     // reallocate internal buffer if the window size has changed
     int size = windowLines() * windowColumns();
     if (_windowBuffer.empty() || _windowBufferSize != size) {
         _windowBufferSize = size;
         _windowBuffer = std::vector<Character>(size);
         _bufferNeedsUpdate = true;
     }
 
     if (!_bufferNeedsUpdate)
         return _windowBuffer;
 
     _screen->getImage(_windowBuffer, size, currentLine(), endWindowLine());
 
     // this window may look beyond the end of the screen, in which
     // case there will be an unused area which needs to be filled
     // with blank characters
     fillUnusedArea();
 
     _bufferNeedsUpdate = false;
     return _windowBuffer;
 }
 
 void ScreenWindow::fillUnusedArea()
 {
     int screenEndLine = _screen->getHistLines() + _screen->getLines() - 1;
     int windowEndLine = currentLine() + windowLines() - 1;
 
     int unusedLines = windowEndLine - screenEndLine;
 
     // stop when unusedLines is negative; there is an issue w/ charsToFill
     //  being greater than an int can hold
     if (unusedLines <= 0) {
         return;
     }
 
     int charsToFill = unusedLines * windowColumns();
 
     Screen::fillWithDefaultChar(std::span(_windowBuffer).subspan(_windowBufferSize - charsToFill), charsToFill);
 }
 
 // return the index of the line at the end of this window, or if this window
 // goes beyond the end of the screen, the index of the line at the end
 // of the screen.
 //
 // when passing a line number to a Screen method, the line number should
 // never be more than endWindowLine()
 //
 int ScreenWindow::endWindowLine() const
 {
     return qMin(currentLine() + windowLines() - 1, lineCount() - 1);
 }
 QVector<LineProperty> ScreenWindow::getLineProperties()
 {
     QVector<LineProperty> result = _screen->getLineProperties(currentLine(), endWindowLine());
 
     if (result.size() != windowLines())
         result.resize(windowLines());
 
     return result;
 }
 
 QString ScreenWindow::selectedText(bool preserveLineBreaks) const
 {
     return _screen->selectedText(preserveLineBreaks);
 }
 
 void ScreenWindow::getSelectionStart(int &column, int &line)
 {
     _screen->getSelectionStart(column, line);
     line -= currentLine();
 }
 void ScreenWindow::getSelectionEnd(int &column, int &line)
 {
     _screen->getSelectionEnd(column, line);
     line -= currentLine();
 }
 void ScreenWindow::setSelectionStart(int column, int line, bool columnMode)
 {
     _screen->setSelectionStart(column, qMin(line + currentLine(), endWindowLine()), columnMode);
 
     _bufferNeedsUpdate = true;
     Q_EMIT selectionChanged();
 }
 
 void ScreenWindow::setSelectionEnd(int column, int line)
 {
     _screen->setSelectionEnd(column, qMin(line + currentLine(), endWindowLine()));
 
     _bufferNeedsUpdate = true;
     Q_EMIT selectionChanged();
 }
 
 bool ScreenWindow::isSelected(int column, int line)
 {
     return _screen->isSelected(column, qMin(line + currentLine(), endWindowLine()));
 }
 
 void ScreenWindow::clearSelection()
 {
     _screen->clearSelection();
 
     Q_EMIT selectionChanged();
 }
 
 void ScreenWindow::setWindowLines(int lines)
 {
     Q_ASSERT(lines > 0);
     _windowLines = lines;
 }
 int ScreenWindow::windowLines() const
 {
     return _windowLines;
 }
 
 int ScreenWindow::windowColumns() const
 {
     return _screen->getColumns();
 }
 
 int ScreenWindow::lineCount() const
 {
     return _screen->getHistLines() + _screen->getLines();
 }
 
 int ScreenWindow::columnCount() const
 {
     return _screen->getColumns();
 }
 
 QPoint ScreenWindow::cursorPosition() const
 {
     QPoint position;
 
     position.setX(_screen->getCursorX());
     position.setY(_screen->getCursorY());
 
     return position;
 }
 
 int ScreenWindow::currentLine() const
 {
     return qBound(0, _currentLine, lineCount() - windowLines());
 }
 
 void ScreenWindow::scrollBy(RelativeScrollMode mode, int amount)
 {
     if (mode == ScrollLines) {
         scrollTo(currentLine() + amount);
     } else if (mode == ScrollPages) {
         scrollTo(currentLine() + amount * (windowLines() / 2));
     }
 }
 
 bool ScreenWindow::atEndOfOutput() const
 {
     return currentLine() == (lineCount() - windowLines());
 }
 
 void ScreenWindow::scrollTo(int line)
 {
     int maxCurrentLineNumber = lineCount() - windowLines();
     line = qBound(0, line, maxCurrentLineNumber);
 
     const int delta = line - _currentLine;
     _currentLine = line;
 
     // keep track of number of lines scrolled by,
     // this can be reset by calling resetScrollCount()
     _scrollCount += delta;
 
     _bufferNeedsUpdate = true;
 
     Q_EMIT scrolled(_currentLine);
 }
 
 void ScreenWindow::setTrackOutput(bool trackOutput)
 {
     _trackOutput = trackOutput;
 }
 
 bool ScreenWindow::trackOutput() const
 {
     return _trackOutput;
 }
 
 int ScreenWindow::scrollCount() const
 {
     return _scrollCount;
 }
 
 void ScreenWindow::resetScrollCount()
 {
     _scrollCount = 0;
 }
 
 QRect ScreenWindow::scrollRegion() const
 {
     bool equalToScreenSize = windowLines() == _screen->getLines();
 
     if (atEndOfOutput() && equalToScreenSize)
         return _screen->lastScrolledRegion();
     else
         return {0, 0, windowColumns(), windowLines()};
 }
 
 void ScreenWindow::notifyOutputChanged()
 {
     // move window to the bottom of the screen and update scroll count
     // if this window is currently tracking the bottom of the screen
     if (_trackOutput) {
         _scrollCount -= _screen->scrolledLines();
         _currentLine = qMax(0, _screen->getHistLines() - (windowLines() - _screen->getLines()));
     } else {
         // if the history is not unlimited then it may
         // have run out of space and dropped the oldest
         // lines of output - in this case the screen
         // window's current line number will need to
         // be adjusted - otherwise the output will scroll
         _currentLine = qMax(0, _currentLine - _screen->droppedLines());
 
         // ensure that the screen window's current position does
         // not go beyond the bottom of the screen
         _currentLine = qMin(_currentLine, _screen->getHistLines());
     }
 
     _bufferNeedsUpdate = true;
 
     Q_EMIT outputChanged();
 }
 
 void ScreenWindow::handleCommandFromKeyboard(KeyboardTranslator::Command command)
 {
     // Keyboard-based navigation
     bool update = false;
 
     // EraseCommand is handled in Vt102Emulation
     if (command & KeyboardTranslator::ScrollPageUpCommand) {
         scrollBy(ScreenWindow::ScrollPages, -1);
         update = true;
     }
     if (command & KeyboardTranslator::ScrollPageDownCommand) {
         scrollBy(ScreenWindow::ScrollPages, 1);
         update = true;
     }
     if (command & KeyboardTranslator::ScrollLineUpCommand) {
         scrollBy(ScreenWindow::ScrollLines, -1);
         update = true;
     }
     if (command & KeyboardTranslator::ScrollLineDownCommand) {
         scrollBy(ScreenWindow::ScrollLines, 1);
         update = true;
     }
     if (command & KeyboardTranslator::ScrollDownToBottomCommand) {
         Q_EMIT scrollToEnd();
         update = true;
     }
     if (command & KeyboardTranslator::ScrollUpToTopCommand) {
         scrollTo(0);
         update = true;
     }
     // TODO: KeyboardTranslator::ScrollLockCommand
     // TODO: KeyboardTranslator::SendCommand
 
     if (update) {
         setTrackOutput(atEndOfOutput());
 
         Q_EMIT outputChanged();
     }
 }
 
 // #include "ScreenWindow.moc"