src/animatedheightwidget.h

   1 /*
   2     This file is part of the KDE project
   3     SPDX-FileCopyrightText: 2024 Felix Ernst <felixernst@kde.org>
   4
   5     SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
   6 */
   7
   8 #ifndef ANIMATEDHEIGHTWIDGET_H
   9 #define ANIMATEDHEIGHTWIDGET_H
  10
  11 #include "global.h"
  12
  13 #include <QPointer>
  14 #include <QWidget>
  15
  16 class QPropertyAnimation;
  17 class QScrollArea;
  18
  19 /**
  20  * @brief An abstract base class which facilitates animated showing and hiding of sub-classes
  21  */
  22 class AnimatedHeightWidget : public QWidget
  23 {
  24 public:
  25     AnimatedHeightWidget(QWidget *parent);
  26
  27     /**
  28      * Plays a show or hide animation while changing visibility.
  29      * Therefore, if this method is used to hide this widget, the actual hiding will be delayed until the animation finished.
  30      *
  31      * @param visible   Whether this bar is supposed to be visible long-term
  32      * @param animated  Whether this should be animated. The animation is skipped if the users' settings are configured that way.
  33      *
  34      * @see QWidget::setVisible()
  35      */
  36     void setVisible(bool visible, Animated animated);
  37
  38     /**
  39      * @returns a QSize with a width of 1 to make sure that this bar never causes side panels to shrink.
  40      *          The returned height equals preferredHeight().
  41      */
  42     QSize sizeHint() const override;
  43
  44 protected:
  45     /**
  46      * AnimatedHeightWidget always requires a singular main child which we call the "contentsContainer".
  47      * Use this method to register such an object.
  48      *
  49      * @returns a "contentsContainer" which is a QWidget that consists of/contains all visible contents of this AnimatedHeightWidget.
  50      *          It will be the only grandchild of this AnimatedHeightWidget.
  51      * @param contentsContainer The object that should be used as the "contentsContainer".
  52      */
  53     QWidget *prepareContentsContainer(QWidget *contentsContainer = new QWidget);
  54
  55     /** @returns whether this object is currently animating a visibility change. */
  56     bool isAnimationRunning() const;
  57
  58 private:
  59     using QWidget::hide; // Use QAbstractAnimation::setVisible() instead.
  60     using QWidget::setVisible; // Makes sure that the setVisible() declaration above doesn't fully hide the one from QWidget so we can still use it privately.
  61     using QWidget::show; // Use QAbstractAnimation::setVisible() instead.
  62
  63     /** @returns the full preferred height this widget should have when it is done animating and visible. */
  64     virtual int preferredHeight() const = 0;
  65
  66 private:
  67     /** @see contentsContainerParent() */
  68     QScrollArea *m_contentsContainerParent = nullptr;
  69
  70     /** @see AnimatedHeightWidget::setVisible() */
  71     QPointer<QPropertyAnimation> m_heightAnimation;
  72 };
  73
  74 #endif // ANIMATEDHEIGHTWIDGET_H