core/boundcomponent: add BoundComponent

This commit is contained in:
outfoxxed 2024-05-01 02:14:32 -07:00
parent d64bf59bb0
commit 3c0456a3c0
Signed by: outfoxxed
GPG key ID: 4C88A185FB89301E
4 changed files with 385 additions and 0 deletions

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@ -25,6 +25,7 @@ qt_add_library(quickshell-core STATIC
iconimageprovider.cpp
imageprovider.cpp
transformwatcher.cpp
boundcomponent.cpp
)
set_source_files_properties(main.cpp PROPERTIES COMPILE_DEFINITIONS GIT_REVISION="${GIT_REVISION}")

258
src/core/boundcomponent.cpp Normal file
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@ -0,0 +1,258 @@
#include "boundcomponent.hpp"
#include <utility>
#include <qcontainerfwd.h>
#include <qlogging.h>
#include <qmetaobject.h>
#include <qobject.h>
#include <qobjectdefs.h>
#include <qqmlcomponent.h>
#include <qqmlcontext.h>
#include <qqmlengine.h>
#include <qqmlerror.h>
#include <qquickitem.h>
#include <qtmetamacros.h>
#include "incubator.hpp"
QObject* BoundComponent::item() const { return this->object; }
QQmlComponent* BoundComponent::sourceComponent() const { return this->mComponent; }
void BoundComponent::setSourceComponent(QQmlComponent* component) {
if (component == this->mComponent) return;
if (this->componentCompleted) {
qWarning() << "BoundComponent.component cannot be set after creation";
return;
}
this->disconnectComponent();
this->ownsComponent = false;
this->mComponent = component;
if (component != nullptr) {
QObject::connect(component, &QObject::destroyed, this, &BoundComponent::onComponentDestroyed);
}
emit this->sourceComponentChanged();
}
void BoundComponent::disconnectComponent() {
if (this->mComponent == nullptr) return;
if (this->ownsComponent) {
delete this->mComponent;
} else {
QObject::disconnect(this->mComponent, nullptr, this, nullptr);
}
this->mComponent = nullptr;
}
void BoundComponent::onComponentDestroyed() { this->mComponent = nullptr; }
QString BoundComponent::source() const { return this->mSource; }
void BoundComponent::setSource(QString source) {
if (source == this->mSource) return;
if (this->componentCompleted) {
qWarning() << "BoundComponent.url cannot be set after creation";
return;
}
auto* context = QQmlEngine::contextForObject(this);
auto* component = new QQmlComponent(context->engine(), context->resolvedUrl(source), this);
if (component->isError()) {
qWarning() << component->errorString().toStdString().c_str();
delete component;
} else {
this->disconnectComponent();
this->ownsComponent = true;
this->mSource = std::move(source);
this->mComponent = component;
emit this->sourceChanged();
emit this->sourceComponentChanged();
}
}
bool BoundComponent::bindValues() const { return this->mBindValues; }
void BoundComponent::setBindValues(bool bindValues) {
if (this->componentCompleted) {
qWarning() << "BoundComponent.bindValues cannot be set after creation";
return;
}
this->mBindValues = bindValues;
emit this->bindValuesChanged();
}
void BoundComponent::componentComplete() {
this->QQuickItem::componentComplete();
this->componentCompleted = true;
this->tryCreate();
}
void BoundComponent::tryCreate() {
if (this->mComponent == nullptr) {
qWarning() << "BoundComponent has no component";
return;
}
auto initialProperties = QVariantMap();
const auto* metaObject = this->metaObject();
for (auto i = metaObject->propertyOffset(); i < metaObject->propertyCount(); i++) {
const auto prop = metaObject->property(i);
if (prop.isReadable()) {
initialProperties.insert(prop.name(), prop.read(this));
}
}
this->incubator = new QsQmlIncubator(QsQmlIncubator::AsynchronousIfNested, this);
this->incubator->setInitialProperties(initialProperties);
// clang-format off
QObject::connect(this->incubator, &QsQmlIncubator::completed, this, &BoundComponent::onIncubationCompleted);
QObject::connect(this->incubator, &QsQmlIncubator::failed, this, &BoundComponent::onIncubationFailed);
// clang-format on
this->mComponent->create(*this->incubator, QQmlEngine::contextForObject(this));
}
void BoundComponent::onIncubationCompleted() {
this->object = this->incubator->object();
delete this->incubator;
this->disconnectComponent();
this->object->setParent(this);
this->mItem = qobject_cast<QQuickItem*>(this->object);
const auto* metaObject = this->metaObject();
const auto* objectMetaObject = this->object->metaObject();
if (this->mBindValues) {
for (auto i = metaObject->propertyOffset(); i < metaObject->propertyCount(); i++) {
const auto prop = metaObject->property(i);
if (prop.isReadable() && prop.hasNotifySignal()) {
const auto objectPropIndex = objectMetaObject->indexOfProperty(prop.name());
if (objectPropIndex == -1) {
qWarning() << "property" << prop.name()
<< "defined on BoundComponent but not on its contained object.";
continue;
}
const auto objectProp = objectMetaObject->property(objectPropIndex);
if (objectProp.isWritable()) {
auto* proxy = new BoundComponentPropertyProxy(this, this->object, prop, objectProp);
proxy->onNotified(); // any changes that might've happened before connection
} else {
qWarning() << "property" << prop.name()
<< "defined on BoundComponent is not writable for its contained object.";
}
}
}
}
for (auto i = metaObject->methodOffset(); i < metaObject->methodCount(); i++) {
const auto method = metaObject->method(i);
if (method.name().startsWith("on") && method.name().length() > 2) {
auto sig = QString(method.methodSignature()).sliced(2);
if (!sig[0].isUpper()) continue;
sig[0] = sig[0].toLower();
auto name = sig.sliced(0, sig.indexOf('('));
auto mostViableSignal = QMetaMethod();
for (auto i = 0; i < objectMetaObject->methodCount(); i++) {
const auto method = objectMetaObject->method(i);
if (method.methodSignature() == sig) {
mostViableSignal = method;
break;
}
if (method.name() == name) {
if (mostViableSignal.isValid()) {
qWarning() << "Multiple candidates, so none will be attached for signal" << name;
goto next;
}
mostViableSignal = method;
}
}
if (!mostViableSignal.isValid()) {
qWarning() << "Function" << method.name() << "appears to be a signal handler for" << name
<< "but it does not match any signals on the target object";
goto next;
}
QMetaObject::connect(
this->object,
mostViableSignal.methodIndex(),
this,
method.methodIndex()
);
}
next:;
}
if (this->mItem != nullptr) {
this->mItem->setParentItem(this);
// clang-format off
QObject::connect(this, &QQuickItem::widthChanged, this, &BoundComponent::updateSize);
QObject::connect(this, &QQuickItem::heightChanged, this, &BoundComponent::updateSize);
QObject::connect(this->mItem, &QQuickItem::implicitWidthChanged, this, &BoundComponent::updateImplicitSize);
QObject::connect(this->mItem, &QQuickItem::implicitHeightChanged, this, &BoundComponent::updateImplicitSize);
// clang-format on
this->updateImplicitSize();
this->updateSize();
}
emit this->loaded();
}
void BoundComponent::onIncubationFailed() {
qWarning() << "Failed to create BoundComponent";
for (auto& error: this->incubator->errors()) {
qWarning() << error;
}
delete this->incubator;
this->disconnectComponent();
}
void BoundComponent::updateSize() { this->mItem->setSize(this->size()); }
void BoundComponent::updateImplicitSize() {
this->setImplicitWidth(this->mItem->implicitWidth());
this->setImplicitHeight(this->mItem->implicitHeight());
}
BoundComponentPropertyProxy::BoundComponentPropertyProxy(
QObject* from,
QObject* to,
QMetaProperty fromProperty,
QMetaProperty toProperty
)
: QObject(from)
, from(from)
, to(to)
, fromProperty(fromProperty)
, toProperty(toProperty) {
const auto* metaObject = this->metaObject();
auto method = metaObject->indexOfSlot("onNotified()");
QMetaObject::connect(from, fromProperty.notifySignal().methodIndex(), this, method);
}
void BoundComponentPropertyProxy::onNotified() {
this->toProperty.write(this->to, this->fromProperty.read(this->from));
}

125
src/core/boundcomponent.hpp Normal file
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@ -0,0 +1,125 @@
#pragma once
#include <qmetaobject.h>
#include <qobject.h>
#include <qqmlcomponent.h>
#include <qqmlparserstatus.h>
#include <qquickitem.h>
#include <qsignalmapper.h>
#include <qtmetamacros.h>
#include "incubator.hpp"
///! Component loader that allows setting initial properties.
/// Component loader that allows setting initial properties, primarily useful for
/// escaping cyclic dependency errors.
///
/// Properties defined on the BoundComponent will be applied to its loaded component,
/// including required properties, and will remain reactive. Functions created with
/// the names of signal handlers will also be attached to signals of the loaded component.
///
/// ```qml {filename="MyComponent.qml"}
/// MouseArea {
/// required property color color;
/// width: 100
/// height: 100
///
/// Rectangle {
/// anchors.fill: parent
/// color: parent.color
/// }
/// }
/// ```
///
/// ```qml
/// BoundComponent {
/// source: "MyComponent.qml"
///
/// // this is the same as assigning to `color` on MyComponent if loaded normally.
/// property color color: "red";
///
/// // this will be triggered when the `clicked` signal from the MouseArea is sent.
/// function onClicked() {
/// color = "blue";
/// }
/// }
/// ```
class BoundComponent: public QQuickItem {
Q_OBJECT;
// clang-format off
/// The loaded component. Will be null until it has finished loading.
Q_PROPERTY(QObject* item READ item NOTIFY loaded);
/// The source to load, as a Component.
Q_PROPERTY(QQmlComponent* sourceComponent READ sourceComponent WRITE setSourceComponent NOTIFY sourceComponentChanged);
/// The source to load, as a Url.
Q_PROPERTY(QString source READ source WRITE setSource NOTIFY sourceChanged);
/// If property values should be bound after they are initially set. Defaults to `true`.
Q_PROPERTY(bool bindValues READ bindValues WRITE setBindValues NOTIFY bindValuesChanged);
Q_PROPERTY(qreal implicitWidth READ implicitWidth NOTIFY implicitWidthChanged);
Q_PROPERTY(qreal implicitHeight READ implicitHeight NOTIFY implicitHeightChanged);
// clang-format on
QML_ELEMENT;
public:
explicit BoundComponent(QQuickItem* parent = nullptr): QQuickItem(parent) {}
void componentComplete() override;
[[nodiscard]] QObject* item() const;
[[nodiscard]] QQmlComponent* sourceComponent() const;
void setSourceComponent(QQmlComponent* sourceComponent);
[[nodiscard]] QString source() const;
void setSource(QString source);
[[nodiscard]] bool bindValues() const;
void setBindValues(bool bindValues);
signals:
void loaded();
void sourceComponentChanged();
void sourceChanged();
void bindValuesChanged();
private slots:
void onComponentDestroyed();
void onIncubationCompleted();
void onIncubationFailed();
void updateSize();
void updateImplicitSize();
private:
void disconnectComponent();
void tryCreate();
QString mSource;
bool mBindValues = true;
QQmlComponent* mComponent = nullptr;
bool ownsComponent = false;
QsQmlIncubator* incubator = nullptr;
QObject* object = nullptr;
QQuickItem* mItem = nullptr;
bool componentCompleted = false;
};
class BoundComponentPropertyProxy: public QObject {
Q_OBJECT;
public:
BoundComponentPropertyProxy(
QObject* from,
QObject* to,
QMetaProperty fromProperty,
QMetaProperty toProperty
);
public slots:
void onNotified();
private:
QObject* from;
QObject* to;
QMetaProperty fromProperty;
QMetaProperty toProperty;
};

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@ -17,5 +17,6 @@ headers = [
"lazyloader.hpp",
"easingcurve.hpp",
"transformwatcher.hpp",
"boundcomponent.hpp",
]
-----