Terminal: Add Terminal plugin

Adds a new Terminal plugin that provides a Terminal pane inside
Qt Creator.

Fixes: QTCREATORBUG-8511
Change-Id: I7eacb3efa2463d7df9f383ae3fc33254fb9019a9
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: hjk <hjk@qt.io>

src/plugins/terminal/terminalwidget.h

@@ -0,0 +1,164 @@
+// Copyright (C) 2022 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0+ OR GPL-3.0 WITH Qt-GPL-exception-1.0
+
+#pragma once
+
+#include "scrollback.h"
+
+#include <utils/terminalhooks.h>
+
+#include <QAbstractScrollArea>
+#include <QAction>
+#include <QTextLayout>
+#include <QTimer>
+
+#include <iptyprocess.h>
+#include <vterm.h>
+
+#include <memory>
+
+namespace Terminal {
+
+class TerminalWidget : public QAbstractScrollArea
+{
+    Q_OBJECT
+public:
+    TerminalWidget(QWidget *parent = nullptr,
+                   const Utils::Terminal::OpenTerminalParameters &openParameters = {});
+
+    void setFont(const QFont &font);
+
+    QAction &copyAction();
+    QAction &pasteAction();
+
+    QAction &clearSelectionAction();
+
+    QAction &zoomInAction();
+    QAction &zoomOutAction();
+
+    void copyToClipboard() const;
+    void pasteFromClipboard();
+
+    void clearSelection();
+
+    void zoomIn();
+    void zoomOut();
+
+    void clearContents();
+
+    struct Selection
+    {
+        QPoint start;
+        QPoint end;
+    };
+
+signals:
+    void started(qint64 pid);
+
+protected:
+    void paintEvent(QPaintEvent *event) override;
+    void keyPressEvent(QKeyEvent *event) override;
+    void resizeEvent(QResizeEvent *event) override;
+    void wheelEvent(QWheelEvent *event) override;
+    void focusInEvent(QFocusEvent *event) override;
+    void focusOutEvent(QFocusEvent *event) override;
+    void inputMethodEvent(QInputMethodEvent *event) override;
+
+    void mousePressEvent(QMouseEvent *event) override;
+    void mouseMoveEvent(QMouseEvent *event) override;
+    void mouseReleaseEvent(QMouseEvent *event) override;
+    void mouseDoubleClickEvent(QMouseEvent *event) override;
+
+    void scrollContentsBy(int dx, int dy) override;
+
+    void showEvent(QShowEvent *event) override;
+
+    bool event(QEvent *event) override;
+
+protected:
+    void onReadyRead();
+    void setupVTerm();
+    void setupFont();
+    void setupPty();
+    void setupColors();
+
+    void writeToPty(const QByteArray &data);
+
+    void createTextLayout();
+
+    // Callbacks from vterm
+    void invalidate(VTermRect rect);
+    int sb_pushline(int cols, const VTermScreenCell *cells);
+    int sb_popline(int cols, VTermScreenCell *cells);
+    int sb_clear();
+    int setTerminalProperties(VTermProp prop, VTermValue *val);
+    int movecursor(VTermPos pos, VTermPos oldpos, int visible);
+
+    const VTermScreenCell *fetchCell(int x, int y) const;
+
+    qreal topMargin() const;
+
+    QPoint viewportToGlobal(QPoint p) const;
+
+    int textLineFromPixel(int y) const;
+    std::optional<int> textPosFromPoint(const QTextLayout &textLayout, QPoint p) const;
+
+    std::optional<QTextLayout::FormatRange> selectionToFormatRange(
+        TerminalWidget::Selection selection, const QTextLayout &layout, int rowOffset) const;
+
+    void applySizeChange();
+
+    void updateScrollBars();
+
+private:
+    std::unique_ptr<IPtyProcess> m_ptyProcess;
+
+    std::unique_ptr<VTerm, void (*)(VTerm *)> m_vterm;
+    VTermScreen *m_vtermScreen;
+    QSize m_vtermSize;
+
+    QFont m_font;
+    QSizeF m_cellSize;
+    qreal m_cellBaseline;
+    qreal m_lineSpacing;
+
+    bool m_altscreen{false};
+    bool m_ignoreScroll{false};
+
+    QString m_preEditString;
+
+    std::optional<Selection> m_selection;
+    QPoint m_selectionStartPos;
+
+    std::unique_ptr<Internal::Scrollback> m_scrollback;
+
+    QTextLayout m_textLayout;
+
+    struct
+    {
+        int row{0};
+        int col{0};
+        bool visible{false};
+    } m_cursor;
+
+    VTermScreenCallbacks m_vtermScreenCallbacks;
+
+    QAction m_copyAction;
+    QAction m_pasteAction;
+
+    QAction m_clearSelectionAction;
+
+    QAction m_zoomInAction;
+    QAction m_zoomOutAction;
+
+    QTimer m_readDelayTimer;
+    int m_readDelayRestarts{0};
+
+    int m_layoutVersion{0};
+
+    std::array<QColor, 18> m_currentColors;
+
+    Utils::Terminal::OpenTerminalParameters m_openParameters;
+};
+
+} // namespace Terminal