src/dolphinnavigatorswidgetaction.h

   1 /*
   2     This file is part of the KDE project
   3     SPDX-FileCopyrightText: 2020 Felix Ernst <fe.a.ernst@gmail.com>
   4
   5     SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
   6 */
   7
   8 #ifndef DOLPHINNAVIGATORSWIDGETACTION_H
   9 #define DOLPHINNAVIGATORSWIDGETACTION_H
  10
  11 #include "dolphinurlnavigator.h"
  12
  13 #include <QPointer>
  14 #include <QSplitter>
  15 #include <QTimer>
  16 #include <QWidgetAction>
  17
  18 #include <memory>
  19
  20 class KXmlGuiWindow;
  21 class QPushButton;
  22
  23 /**
  24  * @brief QWidgetAction that allows to use DolphinUrlNavigators in a toolbar.
  25  *
  26  * This class is mainly a container that manages up to two DolphinUrlNavigator objects so they
  27  * can be added to a toolbar. It also deals with alignment.
  28  *
  29  * The structure of the defaultWidget() of this QWidgetAction is as follows:
  30  * - A QSplitter manages up to two sides which each correspond to one DolphinViewContainer.
  31  *      The secondary side only exists for split view and is created by
  32  *      createSecondaryUrlNavigator() when necessary.
  33  * - Each side is a QWidget which I call NavigatorWidget with a QHBoxLayout.
  34  * - Each NavigatorWidget consists an UrlNavigator, an emptyTrashButton and spacing.
  35  * - Only the primary navigatorWidget has leading spacing. Both have trailing spacing.
  36  *      The spacing is there to align the UrlNavigator with its DolphinViewContainer.
  37  */
  38 class DolphinNavigatorsWidgetAction : public QWidgetAction
  39 {
  40     Q_OBJECT
  41
  42 public:
  43     DolphinNavigatorsWidgetAction(QWidget *parent = nullptr);
  44
  45     /**
  46      * Adjusts the width of the spacings used to align the UrlNavigators with ViewContainers.
  47      * This can only work nicely if up-to-date geometry of ViewContainers is cached so
  48      * followViewContainersGeometry() has to have been called at least once before.
  49      */
  50     void adjustSpacing();
  51
  52     /**
  53      * The secondary UrlNavigator is only created on-demand. Such an action is not necessary
  54      * for the primary UrlNavigator which is created preemptively.
  55      *
  56      * This method should preferably only be called when:
  57      * - Split view is activated in the active tab
  58      * OR
  59      * - A switch to a tab that is already in split view mode is occuring
  60      */
  61     void createSecondaryUrlNavigator();
  62
  63     /**
  64      * Notify this widget of changes in geometry of the ViewContainers it tries to be
  65      * aligned with.
  66      */
  67     void followViewContainersGeometry(QWidget *primaryViewContainer,
  68                                       QWidget *secondaryViewContainer = nullptr);
  69
  70     bool isInToolbar() const;
  71
  72     /**
  73      * @return the primary UrlNavigator.
  74      */
  75     DolphinUrlNavigator *primaryUrlNavigator() const;
  76     /**
  77      * @return the secondary UrlNavigator and nullptr if it doesn't exist.
  78      */
  79     DolphinUrlNavigator *secondaryUrlNavigator() const;
  80
  81     /**
  82      * Change the visibility of the secondary UrlNavigator including spacing.
  83      * @param visible Setting this to false will completely hide the secondary side of this
  84      *                WidgetAction's QSplitter making the QSplitter effectively disappear.
  85      */
  86     void setSecondaryNavigatorVisible(bool visible);
  87
  88 protected:
  89     /**
  90      * There should always ever be one navigatorsWidget for this action so
  91      * this method always returns the same widget and reparents it.
  92      * You normally don't have to use this method directly because
  93      * QWidgetAction::requestWidget() is used to obtain the navigatorsWidget
  94      * and to steal it from whereever it was prior.
  95      * @param parent the new parent of the navigatorsWidget.
  96      */
  97     QWidget *createWidget(QWidget *parent) override;
  98
  99     /** @see QWidgetAction::deleteWidget() */
 100     void deleteWidget(QWidget *widget) override;
 101
 102 private:
 103     /**
 104      * In Left-to-right languages the Primary side will be the left one.
 105      */
 106     enum Side {
 107         Primary,
 108         Secondary
 109     };
 110     /**
 111      * Used to create the navigatorWidgets for both sides of the QSplitter.
 112      */
 113     QWidget *createNavigatorWidget(Side side) const;
 114
 115     /**
 116      * Used to retrieve the emptyTrashButtons for the navigatorWidgets on both sides.
 117      */
 118     QPushButton *emptyTrashButton(Side side);
 119
 120     /**
 121      * Creates a new empty trash button.
 122      * @param urlNavigator Only when this UrlNavigator shows the trash directory
 123      *                     will the button be visible.
 124      * @param parent       Aside from the usual QObject deletion mechanisms,
 125      *                     this parameter influences the positioning of dialog windows
 126      *                     pertaining to this trash button.
 127      */
 128     QPushButton *newEmptyTrashButton(const DolphinUrlNavigator *urlNavigator, QWidget *parent) const;
 129
 130     enum Position {
 131         Leading,
 132         Trailing
 133     };
 134     /**
 135      * Used to retrieve both the leading and trailing spacing for the navigatorWidgets
 136      * on both sides. A secondary leading spacing does not exist.
 137      */
 138     QWidget *spacing(Side side, Position position) const;
 139
 140     /**
 141      * Sets this action's text depending on the amount of visible UrlNavigators.
 142      */
 143     void updateText();
 144
 145     /**
 146      * The defaultWidget() of this QWidgetAction.
 147      */
 148     std::unique_ptr<QSplitter> m_splitter;
 149
 150     /**
 151      * adjustSpacing() has to be called slightly later than when urlChanged is emitted.
 152      * This timer bridges that time.
 153      */
 154     std::unique_ptr<QTimer> m_adjustSpacingTimer;
 155
 156     /**
 157      * Extracts the geometry information needed by adjustSpacing() from
 158      * ViewContainers. They are also monitored for size changes which
 159      * will lead to adjustSpacing() calls.
 160      */
 161     class ViewGeometriesHelper : public QObject
 162     {
 163     public:
 164         /**
 165          * @param navigatorsWidget       The QWidget of the navigatorsWidgetAction.
 166          * @param navigatorsWidgetAction is only used to call adjustSpacing() whenever that is
 167          *                               deemed necessary.
 168          */
 169         ViewGeometriesHelper(QWidget *navigatorsWidget, DolphinNavigatorsWidgetAction *navigatorsWidgetAction);
 170
 171         /**
 172          * Calls m_navigatorsWidgetAction::adjustSpacing() when a watched object is resized.
 173          */
 174         bool eventFilter(QObject *watched, QEvent *event) override;
 175
 176         /**
 177          * Sets the ViewContainers whose geometry is obtained when viewGeometries() is called.
 178          */
 179         void setViewContainers(QWidget *primaryViewContainer,
 180                                QWidget *secondaryViewContainer = nullptr);
 181
 182         struct Geometries {
 183             int globalXOfNavigatorsWidget;
 184             int globalXOfPrimary;
 185             int widthOfPrimary;
 186             int globalXOfSecondary;
 187             int widthOfSecondary;
 188         };
 189         /**
 190          * @return a Geometries struct that contains values adjustSpacing() requires.
 191          */
 192         Geometries viewGeometries();
 193
 194     private:
 195         QWidget *m_navigatorsWidget;
 196         /** Is only used to call adjustSpacing() whenever that is deemed necessary. */
 197         DolphinNavigatorsWidgetAction *m_navigatorsWidgetAction;
 198
 199         QPointer<QWidget> m_primaryViewContainer;
 200         QPointer<QWidget> m_secondaryViewContainer;
 201     };
 202
 203     ViewGeometriesHelper m_viewGeometriesHelper;
 204 };
 205
 206 #endif // DOLPHINNAVIGATORSWIDGETACTION_H