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

 /*
     SPDX-FileCopyrightText: 2007-2008 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.
 */
 
 #ifndef SCREENWINDOW_H
 #define SCREENWINDOW_H
 
 // Qt
 #include <QObject>
 #include <QPoint>
 #include <QRect>
 
 // Konsole
 #include "Character.h"
 #include "KeyboardTranslator.h"
 
 namespace Konsole
 {
 
 class Screen;
 
 /**
  * Provides a window onto a section of a terminal screen.  A terminal widget can then render
  * the contents of the window and use the window to change the terminal screen's selection
  * in response to mouse or keyboard input.
  *
  * A new ScreenWindow for a terminal session can be created by calling Emulation::createWindow()
  *
  * Use the scrollTo() method to scroll the window up and down on the screen.
  * Use the getImage() method to retrieve the character image which is currently visible in the window.
  *
  * setTrackOutput() controls whether the window moves to the bottom of the associated screen when new
  * lines are added to it.
  *
  * Whenever the output from the underlying screen is changed, the notifyOutputChanged() slot should
  * be called.  This in turn will update the window's position and Q_EMIT the outputChanged() signal
  * if necessary.
  */
 class ScreenWindow : public QObject
 {
     Q_OBJECT
 
 public:
     /**
      * Constructs a new screen window with the given parent.
      * A screen must be specified by calling setScreen() before calling getImage() or getLineProperties().
      *
      * You should not call this constructor directly, instead use the Emulation::createWindow() method
      * to create a window on the emulation which you wish to view.  This allows the emulation
      * to notify the window when the associated screen has changed and synchronize selection updates
      * between all views on a session.
      */
     ScreenWindow(QObject *parent = nullptr);
     ~ScreenWindow() override;
 
     /** Sets the screen which this window looks onto */
     void setScreen(Screen *screen);
     /** Returns the screen which this window looks onto */
     Screen *screen() const;
 
     /**
      * Returns the image of characters which are currently visible through this window
      * onto the screen.
      *
      * The returned buffer is managed by the ScreenWindow instance and does not need to be
      * deleted by the caller.
      */
     std::span<Character> getImage();
 
     /**
      * Returns the line attributes associated with the lines of characters which
      * are currently visible through this window
      */
     QVector<LineProperty> getLineProperties();
 
     /**
      * Returns the number of lines which the region of the window
      * specified by scrollRegion() has been scrolled by since the last call
      * to resetScrollCount().  scrollRegion() is in most cases the
      * whole window, but will be a smaller area in, for example, applications
      * which provide split-screen facilities.
      *
      * This is not guaranteed to be accurate, but allows views to optimize
      * rendering by reducing the amount of costly text rendering that
      * needs to be done when the output is scrolled.
      */
     int scrollCount() const;
 
     /**
      * Resets the count of scrolled lines returned by scrollCount()
      */
     void resetScrollCount();
 
     /**
      * Returns the area of the window which was last scrolled, this is
      * usually the whole window area.
      *
      * Like scrollCount(), this is not guaranteed to be accurate,
      * but allows views to optimize rendering.
      */
     QRect scrollRegion() const;
 
     /**
      * Sets the start of the selection to the given @p line and @p column within
      * the window.
      */
     void setSelectionStart(int column, int line, bool columnMode);
     /**
      * Sets the end of the selection to the given @p line and @p column within
      * the window.
      */
     void setSelectionEnd(int column, int line);
     /**
      * Retrieves the start of the selection within the window.
      */
     void getSelectionStart(int &column, int &line);
     /**
      * Retrieves the end of the selection within the window.
      */
     void getSelectionEnd(int &column, int &line);
     /**
      * Returns true if the character at @p line , @p column is part of the selection.
      */
     bool isSelected(int column, int line);
     /**
      * Clears the current selection
      */
     void clearSelection();
 
     /** Sets the number of lines in the window */
     void setWindowLines(int lines);
     /** Returns the number of lines in the window */
     int windowLines() const;
     /** Returns the number of columns in the window */
     int windowColumns() const;
 
     /** Returns the total number of lines in the screen */
     int lineCount() const;
     /** Returns the total number of columns in the screen */
     int columnCount() const;
 
     /** Returns the index of the line which is currently at the top of this window */
     int currentLine() const;
 
     /**
      * Returns the position of the cursor
      * within the window.
      */
     QPoint cursorPosition() const;
 
     /**
      * Convenience method. Returns true if the window is currently at the bottom
      * of the screen.
      */
     bool atEndOfOutput() const;
 
     /** Scrolls the window so that @p line is at the top of the window */
     void scrollTo(int line);
 
     /** Describes the units which scrollBy() moves the window by. */
     enum RelativeScrollMode {
         /** Scroll the window down by a given number of lines. */
         ScrollLines,
         /**
          * Scroll the window down by a given number of pages, where
          * one page is windowLines() lines
          */
         ScrollPages
     };
 
     /**
      * Scrolls the window relative to its current position on the screen.
      *
      * @param mode Specifies whether @p amount refers to the number of lines or the number
      * of pages to scroll.
      * @param amount The number of lines or pages ( depending on @p mode ) to scroll by.  If
      * this number is positive, the view is scrolled down.  If this number is negative, the view
      * is scrolled up.
      */
     void scrollBy(RelativeScrollMode mode, int amount);
 
     /**
      * Specifies whether the window should automatically move to the bottom
      * of the screen when new output is added.
      *
      * If this is set to true, the window will be moved to the bottom of the associated screen ( see
      * screen() ) when the notifyOutputChanged() method is called.
      */
     void setTrackOutput(bool trackOutput);
     /**
      * Returns whether the window automatically moves to the bottom of the screen as
      * new output is added.  See setTrackOutput()
      */
     bool trackOutput() const;
 
     /**
      * Returns the text which is currently selected.
      *
      * @param preserveLineBreaks See Screen::selectedText()
      */
     QString selectedText(bool preserveLineBreaks) const;
 
 public Q_SLOTS:
     /**
      * Notifies the window that the contents of the associated terminal screen have changed.
      * This moves the window to the bottom of the screen if trackOutput() is true and causes
      * the outputChanged() signal to be emitted.
      */
     void notifyOutputChanged();
 
     void handleCommandFromKeyboard(KeyboardTranslator::Command command);
 
 Q_SIGNALS:
     /**
      * Emitted when the contents of the associated terminal screen (see screen()) changes.
      */
     void outputChanged();
 
     /**
      * Emitted when the screen window is scrolled to a different position.
      *
      * @param line The line which is now at the top of the window.
      */
     void scrolled(int line);
 
     /** Emitted when the selection is changed. */
     void selectionChanged();
 
     void scrollToEnd();
 
 private:
     int endWindowLine() const;
     void fillUnusedArea();
 
     // not owned by us
     Screen *_screen; // see setScreen() , screen()
     std::vector<Character> _windowBuffer;
     int _windowBufferSize;
     bool _bufferNeedsUpdate;
 
     int _windowLines;
     int _currentLine; // see scrollTo() , currentLine()
     bool _trackOutput; // see setTrackOutput() , trackOutput()
     int _scrollCount; // count of lines which the window has been scrolled by since
                       // the last call to resetScrollCount()
 };
 
 }
 #endif // SCREENWINDOW_H