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oak-editor/effects/effectfield.h
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/***
Olive - Non-Linear Video Editor
Copyright (C) 2019 Olive Team
This program 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.
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, see <http://www.gnu.org/licenses/>.
***/
#ifndef EFFECTFIELD_H
#define EFFECTFIELD_H
#include <QObject>
#include <QVariant>
#include <QVector>
#include "effects/keyframe.h"
#include "undo/undostack.h"
#include "nodes/nodedatatypes.h"
class EffectRow;
class ComboAction;
/**
* @brief The EffectField class
*
* Any user-interactive element of an Effect. Usually a parameter that modifies the effect output, but sometimes just
* a UI object that performs some other function (e.g. LabelField and ButtonField).
*
* EffectField provides a largely abstract interface for Effect classes to pull information from. The class itself
* handles keyframing between linear, bezier, and hold interpolation accessible through GetValueAt(). This class
* is abstract, and therefore never intended to be used on its own. Instead you should always use a derived class.
*
* EffectField objects are *not* UI objects on their own. Instead, they're largely a system of values that can change
* over time. For a widget that the user can use to edit/modify these values, use CreateWidget().
*
* Derived classes are expected to override at least CreateWidget() to create a visual interactive widget corresponding
* to the field. If this
* field is a value used in the Effect (as most will be), UpdateWidgetValue() should also be overridden to display the
* correct value for this field as the user moves around the Timeline.
*
* If the field is intended to be saved and loaded from Olive project files (as most will be), ConvertStringToValue()
* and ConvertValueToString() may also have to be overridden depending on how the derived class's data works.
*/
class EffectField : public QObject {
Q_OBJECT
public:
/**
* @brief The EffectFieldType enum
*
* Predetermined types of fields. Used throughout Olive to identify what kind of data to expect from GetValueAt().
*
* This enum is also currently used to match an external XML effect's fields with the correct derived class (e.g.
* EFFECT_FIELD_DOUBLE matches to DoubleField).
*/
enum EffectFieldType {
/** Values are doubles. Also corresponds to DoubleField. */
EFFECT_FIELD_DOUBLE,
/** Values are colors. Also corresponds to ColorField. */
EFFECT_FIELD_COLOR,
/** Values are strings. Also corresponds to StringField. */
EFFECT_FIELD_STRING,
/** Values are booleans. Also corresponds to BoolField. */
EFFECT_FIELD_BOOL,
/** Values are arbitrary data. Also corresponds to ComboField. */
EFFECT_FIELD_COMBO,
/** Values are font family names (in string). Also corresponds to FontField. */
EFFECT_FIELD_FONT,
/** Values are filenames (in string). Also corresponds to FileField. */
EFFECT_FIELD_FILE,
/** Values is a UI object with no data. Corresponds to nothing. */
EFFECT_FIELD_UI
};
/**
* @brief EffectField Constructor
*
* Creates a new EffectField object.
*
* @param parent
*
* The EffectRow to add this field to. This must be a valid EffectRow. The EffectRow takes ownership of the field
* using the QObject parent/child system to automate memory management. EffectFields are never expected
* to change parent during their lifetime.
*
* @param t
*
* The type of data contained within this field. This is expected to be filled by a derived class.
*/
EffectField(EffectRow* parent, EffectFieldType t);
/**
* @brief Get the EffectRow that this field is a member of.
*
* Equivalent to `static_cast<EffectRow*>(EffectField::parent())`
*
* @return
*
* The EffectRow that this field is a member of.
*/
EffectRow* GetParentRow();
/**
* @brief Get the type of data to expect from this field
*
* @return
*
* A member of the EffectFieldType enum.
*/
const EffectFieldType& type();
/**
* @brief Get the value of this field at a given timecode
*
* EffectFields are designed to be keyframable, meaning the user can make the values change over the course of the
* Sequence. This is the main function used through Olive to retrieve what value this field will be at a given time.
*
* A common use case for this function would be EffectField::GetValueAt(EffectField::Now()), which will automatically
* retrieve the timecode at the current playhead.
*
* If the parent EffectRow is NOT keyframing, this function will simply return persistent_data_. If it IS keyframing,
* this will use the values in `keyframes` to determine what value should be specifically at this time.
* (bezier or linear interpolating it between values if necessary). Therefore this function should almost always be
* used to retrieve data from this field as the value will always be correct for the given time.
*
* @param timecode
*
* The time to retrieve the value in clip/media seconds (e.g. 0.0 is the very start of the media, 1.0 is one second
* into the media).
*
* @return
*
* A QVariant representation of the value at the given timecode.
*/
QVariant GetValueAt(double timecode);
/**
* @brief Set the value of this field at a given timecode
*
* EffectFields are designed to be keyframable, meaning the user can make the values change over the course of the
* Sequence. This is the main function used through Olive to set what value this field will be at a given time.
*
* If the parent EffectRow is keyframing, this function will determine whether a keyframe exists at this time already.
* If it does, it will change the value at that keyframe to `value`. Otherwise, it'll create a new keyframe at the
* specified `time` with the specified `value`.
*
* If the parent EffectRow is not keyframing, the data is simply stored in `persistent_data_`.
*
* When constructing an Effect
*
* @param time
*
* The time to retrieve the value at in clip/media seconds (e.g. 0.0 is the very start of the media, 1.0 is one
* second into the media).
*
* @param value
*
* The QVariant value to set at this time.
*/
void SetValueAt(double time, const QVariant& value);
/**
* @brief Set up keyframing on this field
*
* This should always be called if the user is enabling/disabling keyframing on the parent row. This function will
* move data between persistent_data_ and keyframes depending on whether keyframing is being enabled or disabled.
*
* If keyframing is getting ENABLED, this function will create the first keyframe automatically at the current time
* using the current value in persistent_data_.
*
* If keyframing is getting DISABLED, persistent_data_ is set to the current value at this time (GetValueAt(Now()))
* and delete all current keyframes.
*
* @param enabled
*
* TRUE if keyframing is getting enabled.
*
* @param ca
*
* A valid ComboAction object. It's expected that this function will be part of a larger action to enable/disable
* keyframing on the parent EffectRow, so this function will add commands to this ComboAction.
*/
void PrepareDataForKeyframing(bool enabled, ComboAction* ca);
/**
* @brief Convert a value from this field to a string
*
* When saving effect data to a project file, the data needs to be converted to a string format for saving in XML.
* The needs of this string representation may differ depending on the needs of the derived class, therefore you
* derived classes may need to override it.
*
* Default behavior is a simple QVariant <-> QString conversion, which should suffice in most cases.
*
* @param v
*
* The QVariant data (retrieved from this field) to convert to string
*
* @return
*
* A string representation of the QVariant data provided.
*/
virtual QString ConvertValueToString(const QVariant& v);
/**
* @brief Convert a string to a value appropriate for this field
*
* This function is the inverse of ConvertValueToString(), converting a string back to field data.
*
* @param s
*
* The string to convert to data.
*
* @return
*
* QVariant data converted from the provided string.
*/
virtual QVariant ConvertStringToValue(const QString& s);
/**
* @brief Create a widget for the user to interact with this field
*
* EffectField objects are *not* UI objects on their own. Instead, they're largely a system of values that can change
* over time. This function creates a QWidget object that can be placed somewhere in the UI so the user can
* interact with and change the data in this field.
*
* This function must be overridden by derived classes in order to create a widget that appropriate for that field's
* data. The derived class is also responsible for
* connecting signals like EnabledChanged(), Clicked(), and any other data that needs to be transferred between the
* widget and the field (setting up the signals and slots to do so). The field does NOT retain ownership (or any
* reference for that matter) to widgets it creates,
* so keeping the widget and field up to date with each other relies solely on setting up signals and slots.
* Infinite widgets can be created from a single field and used throughout Olive this way.
*
* Ownership is passed to the caller, and therefore the caller is responsible for freeing it.
*
* @param existing
*
* Olive allows multiple effects to attach to one UI layout. Pass a QWidget to this parameter (instead of nullptr)
* to attach this field additionally to the widget's signals/slots without creating a new one. The QWidget must be a
* widget previously created from the same derived class type or the result is undefined.
*
* @return
*
* A new QWidget object for this EffectField, or the same QWidget passed to `existing` if one was specified.
*/
virtual QWidget* CreateWidget(QWidget* existing = nullptr) = 0;
/**
* @brief Update a widget created by CreateWidget() using the value at a given time
*
* Use this function to update a QWidget (obtained from CreateWidget()) with the correct value from the field at a
* given time.
*
* Since only the derived classes know what type of QWidget it created in CreateWidget() and how to work with them,
* derived classes are also expected to override this function if the field is an active value used in the Effect
* that should visually update as the user moves around the Timeline. However if the field does NOT need to update
* live (e.g. the field is just a UI wrapper like LabelField or ButtonField), this function does not need to be
* overridden as the default behavior (to do nothing) will suffice in those cases.
*
* @param widget
*
* The QWidget to set the value of (must be a QWidget obtained from CreateWidget() or the behavior is undefined).
*
* @param timecode
*
* The time in clip/media seconds to retrieve data from.
*/
virtual void UpdateWidgetValue(QWidget* widget, double timecode);
/**
* @brief Get the correct X position/time value of a bezier keyframe's handles
*
* Retrieves the X value (time value) of a bezier keyframe's handles. Internally, the handles' X values are allowed
* to be arbitrary values. This however can lead to inadvertently creating impossible bezier curves (ones that, for
* example, mathematically loop over each other, but obviously a field can't have two values at the same time).
*
* This function returns the keyframe handles' X values adjusted to prevent this from happening. All calculations
* are consistent (i.e. the post handle of one keyframe will be adjusted the same way as the pre handle of the
* keyframe before it). It's recommended to always use this function to retrieve keyframe handle X values.
*
* @param key
*
* Index of the keyframe (in `keyframes`) to retrieve the handle position from.
*
* @param post
*
* FALSE to retrieve the "pre" handle (handle to the left of the keyframe), TRUE to retrieve the "post" handle
* (handle to the right of the keyframe).
*
* @return
*
* The adjusted X value of that keyframe handle.
*/
double GetValidKeyframeHandlePosition(int key, bool post);
/**
* @brief Return whether this field is enabled or not
*
* @return
*
* TRUE if this field is enabled.
*/
bool IsEnabled();
/**
* @brief Set the enabled state of this field
* @param e
*
* TRUE to enable this field, FALSE to disable it.
*/
void SetEnabled(bool e);
/**
* @brief Persistent data object
*
* If the parent EffectRow is not keyframing, all field data is stored and retrieved here. If the row IS keyframing,
* this variable goes basically unused unless `keyframes` is empty.
*
* NOTE: It is NOT recommended to access this variable directly. Use GetValueAt() instead.
*/
QVariant persistent_data_;
/**
* @brief Keyframe array
*
* Contains all data about this field's keyframes, from the keyframe times, to their data, to their type (linear,
* bezier, or hold), to the bezier handles (if using bezier). If the row is not keyframing, this array is never used
* (`persistent_data_` is used instead). If it is, this array will always be used unless the array is empty, in which
* case `persistent_data_` will be used again.
*/
QVector<EffectKeyframe> keyframes;
signals:
/**
* @brief Changed signal
*
* Emitted whenever SetValueAt() is called in order to trigger a UI update and Viewer repaint. Note this is NOT
* triggered as the value changes from keyframing. Only when the user themselves triggers a change.
*/
void Changed();
/**
* @brief Clicked signal
*
* Emitted when the user clicks on a QWidget attached to this field. Derived classes should connect this to the
* clicked signal of any QWidget's created (or attached) in CreateWidget().
*/
void Clicked();
/**
* @brief Enable change state signal
*
* Emitted when the field's enabled state is changed through SetEnabled(). Derived classes should connect this to the
* setEnabled() slot of any QWidget's created (or attached) in CreateWidget().
*/
void EnabledChanged(bool);
private:
/**
* @brief Internal type variable set in the constructor. Access with type().
*/
EffectFieldType type_;
/**
* @brief Used by GetValueAt() to determine whether to use keyframe data or persistent data
* @return
*
* TRUE if this keyframe data should be retrieved, FALSE if persistent data should be retrieved
*/
bool HasKeyframes();
/**
* @brief Convert clip time in frames to clip time in seconds
*
* @param frame
*
* Clip time in frames
*
* @return
*
* Clip time in seconds
*/
double FrameToSeconds(long frame);
/**
* @brief Convert clip time in seconds to clip time in frames
*
* @param seconds
*
* Clip time in seconds
*
* @return
*
* Clip time in frames
*/
long SecondsToFrame(double seconds);
/**
* @brief Internal function for determining where we are between the available keyframes
*
* @param timecode
*
* Timecode to get keyframe data at
*
* @param before
*
* The index (in the keyframes array) in the keyframe prior to this timecode.
*
* @param after
*
* The index (in the keyframes array) in the keyframe after this timecode.
*
* @param d
*
* The progress between the `before` keyframe and `after` keyframe from 0.0 to 1.0.
*/
void GetKeyframeData(double timecode, int& before, int& after, double& d);
/**
* @brief Internal enabled value
*/
bool enabled_;
};
#endif // EFFECTFIELD_H