src/Tabs/ContentTab.h

/************************************************************************
**
**  Copyright (C) 2015-2020 Kevin B. Hendricks, Stratford, Ontario Canada
**  Copyright (C) 2009-2011 Strahinja Markovic  <strahinja.markovic@gmail.com>
**
**  This file is part of Sigil.
**
**  Sigil 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.
**
**  Sigil 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 Sigil.  If not, see <http://www.gnu.org/licenses/>.
**
*************************************************************************/

#pragma once
#ifndef CONTENTTAB_H
#define CONTENTTAB_H

#include <QWidget>
#include <QString>
#include <QtCore/QUrl>

#include "Misc/Utility.h"
#include "ViewEditors/Zoomable.h"

class QLayout;
class Searchable;
class Resource;

/**
 * A generic tab widget for editing/viewing a resource.
 */
class ContentTab : public QWidget, public Zoomable
{
    Q_OBJECT

public:

    /**
     * Constructor.
     *
     * @param resource The resource this tab will be displaying.
     * @param parent The parent of this QObject.
     */
    ContentTab(Resource *resource, QWidget *parent = 0);

    /**
     * Destructor.
     */
    virtual ~ContentTab();

    /**
     * Returns the filename of the displayed resource.
     *
     * @return The filename of the displayed resource.
     */
    QString GetFilename();

    QString GetShortPathName();

    /**
     * Returns the icon appropriate for the displayed resource.
     *
     * @return The icon appropriate for the displayed resource.
     */
    QIcon GetIcon();

    /**
     * The resource currently loaded in the tab.
     *
     * @return A reference to the resource.
     */
    Resource *GetLoadedResource();

    /**
     * The modification state of the resource.
     *
     * @return \c true if the tab has modified the resource.
     */
    virtual bool IsModified()           {
        return false;
    }

    /**
     * Can the user perform the Cut clipboard operation.
     *
     * @return \c true if the user can Cut.
     */
    virtual bool CutEnabled()           {
        return false;
    }

    /**
     * Can the user perform the Copy clipboard operation.
     *
     * @return \c true if the user can Copy.
     */
    virtual bool CopyEnabled()          {
        return false;
    }

    /**
     * Can the user perform the Paste clipboard operation.
     *
     * @return \c true if the user can Paste.
     */
    virtual bool PasteEnabled()         {
        return false;
    }

    virtual bool DeleteLineEnabled()         {
        return false;
    }

    /*
     * Can the user perform the Cut Code Tags operation.
     *
     * @return \c true if the user can Cut.
     */
    virtual bool RemoveFormattingEnabled()          {
        return false;
    }

        /*
     * Can the user perform the Cut Tag Pair operation.
     *
     * @return \c true if the user can Cut.
     */
    virtual bool RemoveTagPairEnabled()          {
        return false;
    }

    /*
     * Can the user perform the Cut Code Tags operation.
     *
     * @return \c true if the user can Cut.
     */
    virtual bool InsertClosingTagEnabled()   {
        return false;
    }

    virtual bool AddToIndexEnabled()   {
        return false;
    }
    virtual bool MarkForIndexEnabled() {
        return false;
    }

    virtual bool InsertIdEnabled() {
        return false;
    }
    virtual bool InsertHyperlinkEnabled() {
        return false;
    }
    virtual bool InsertSpecialCharacterEnabled() {
        return false;
    }
    virtual bool InsertFileEnabled() {
        return false;
    }
    virtual bool ToggleAutoSpellcheckEnabled() {
        return false;
    }

    /**
     * Checked state of the CodeView action.
     *
     * @return \c true if the CodeView action should be checked.
     */
    virtual bool CodeViewChecked()      {
        return false;
    }

    virtual QString GetCaretLocationUpdate() const {
        return QString();
    }

    virtual int GetCursorPosition() const {
        return 0;
    }
    virtual int GetCursorLine() const {
        return 0;
    }
    virtual int GetCursorColumn() const {
        return 0;
    }

    virtual float GetZoomFactor() const {
        return 1.0;
    }
    virtual void SetZoomFactor(float new_zoom_factor) { }

    /**
     * Update content displayed in the tab.
     *
     * For example after a zoom operation.
     */
    virtual void UpdateDisplay() {}

    /**
     * Returns a pointer to searchable content in the tab.
     * Returns pointer instead of reference because we need
     * to return NULL for tabs with no searchable content.
     *
     * @return The searchable content.
     */
    virtual Searchable *GetSearchableContent();

    virtual bool IsLoadingFinished() {
        return true;
    }

    /**
     * Checked state of the Bold action.
     *
     * @return \c true if the Bold action should be checked.
     */
    virtual bool BoldChecked()          {
        return false;
    }

    /**
     * Checked state of the Italic action.
     *
     * @return \c true if the Italic action should be checked.
     */
    virtual bool ItalicChecked()        {
        return false;
    }

    /**
     * Checked state of the Underline action.
     *
     * @return \c true if the Underline action should be checked.
     */
    virtual bool UnderlineChecked()     {
        return false;
    }

    /**
     * Checked state of the Strikethrough action.
     *
     * @return \c true if the Strikethrough action should be checked.
     */
    virtual bool StrikethroughChecked() {
        return false;
    }

    /**
     * Checked state of the Subscrip action.
     *
     * @return \c true if the Subscrip action should be checked.
     */
    virtual bool SubscriptChecked() {
        return false;
    }

    /**
     * Checked state of the Superscript action.
     *
     * @return \c true if the Superscript action should be checked.
     */
    virtual bool SuperscriptChecked() {
        return false;
    }

    virtual bool AlignLeftChecked()     {
        return false;
    }
    virtual bool AlignRightChecked()    {
        return false;
    }
    virtual bool AlignCenterChecked()   {
        return false;
    }
    virtual bool AlignJustifyChecked()  {
        return false;
    }

    /**
     * Checked state of the BulletList action.
     *
     * @return \c true if the BulletList action should be checked.
     */
    virtual bool BulletListChecked()    {
        return false;
    }

    /**
     * Checked state of the NumberList action.
     *
     * @return \c true if the NumberList action should be checked.
     */
    virtual bool NumberListChecked()    {
        return false;
    }

    /**
     * Returns the name of the element the caret is located in.
     *
     * @return The name of the element the caret is located in.
     */
    virtual QString GetCaretElementName() {
        return "";
    }

    virtual bool MarkSelection() {
        return false;
    }

    virtual bool ClearMarkedText() {
        return false;
    }


public slots:

    /**
     * Saves the tab data, then schedules tab for deletion.
     */
    void Close();

    /**
     * Saves the changed content when the user leaves the tab.
     */
    virtual void SaveTabContent();

    /**
     * Loads the resource content when the user enters the tab.
     */
    virtual void LoadTabContent();

    /**
     * Emits the CentralTabRequest signal.
     */
    void EmitCentralTabRequest();

    /**
     * Refresh display after external change of contents
     * (Replace in All Files).
     */
    void ContentChangedExternally();

    /**
     * Change casing of the selected text.
     */
    virtual void ChangeCasing(const Utility::Casing casing);

    /**
     * Returns state of underlying resource
     */
    bool GetResourceWasDeleted();

signals:

    /**
     * Emitted when the tab wants to be deleted.
     *
     * @param tab_to_delete A pointer to this tab.
     */
    void DeleteMe(ContentTab *tab_to_delete);

    /**
     * Emitted when the zoom factor changes.
     *
     * @param factor The new zoom factor.
     */
    void ZoomFactorChanged(float factor);

    /**
     * Emitted when the content of the tab changes.
     */
    void ContentChanged();

    /**
     * Emitted when tab header text has been changed.
     *
     * @param renamed_tab Pointer to this tab.
     */
    void TabRenamed(ContentTab *renamed_tab);

    /**
     * Emitted when the tab wants to become the
     * central (shown) tab of the UI.
     *
     * @param tab The tab that wants to become central.
     */
    void CentralTabRequest(ContentTab *tab);

    /**
     * Emitted when the cursor position changes.
     *
     * Not all tabs have a cursor so this won't be emitted by
     * all tabs.
     *
     * @param line The line the cursor is at.
     * @param column The column the cursor is at.
     */
    void UpdateCursorPosition(int line, int column);

    /**
     * Emitted when we want to do some operations with the clipboard
     * to paste things into elsewhere, but restoring state afterwards
     * so that Clipboard History and current clipboard contents are
     * left unaffected.
     */
    void ClipboardSaveRequest();
    void ClipboardRestoreRequest();

    void SpellingHighlightRefreshRequest();

    void InsertedFileOpenedExternally(const QString &pathname);

    void InsertedFileSaveAs(const QUrl &url);

    void ShowStatusMessageRequest(const QString &message);

    void MarkSelectionRequest();
    void ClearMarkedTextRequest();

protected slots:

    /**
     * Invoked when underlying resource sends out its Deleted signal
     */
    void UnderlyingResourceDeleted();

    /**
     * Emits the DeleteMe signal.
     */
    void EmitDeleteMe();

    /**
     * Emits the TabRenamed signal.
     */
    void EmitTabRenamed();

protected:

    /**
     * A custom focusIn handler.
     * By default, calls the LoadTabContent function.
     *
     * @warning Will \b not be called for child tabs
     *          that set a focus proxy (like FlowTab, TextTab etc.)
     */
    virtual void focusInEvent(QFocusEvent *event);

    /**
     * A custom focusOut handler.
     * By default, calls the SaveTabContent function.
     *
     * @warning Will \b not be called for child tabs
     *          that set a focus proxy (like FlowTab, TextTab etc.)
     */
    virtual void focusOutEvent(QFocusEvent *event);


    ///////////////////////////////
    // PROTECTED MEMBER VARIABLES
    ///////////////////////////////

    /**
     * The resource being displayed.
     */
    Resource *m_Resource;

    /**
     * The main layout of the widget.
     */
    QLayout *m_Layout;

    /**
     * Has our underlying resource been deleted
     */
    bool m_resource_was_deleted;

};

#endif // CONTENTTAB_H