tdesktop/Telegram/SourceFiles/core/click_handler.h

192 lines
5.1 KiB
C++

/*
This file is part of Telegram Desktop,
the official desktop application for the Telegram messaging service.
For license and copyright information please follow this link:
https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
*/
#pragma once
class ClickHandler;
using ClickHandlerPtr = std::shared_ptr<ClickHandler>;
struct ClickContext {
Qt::MouseButton button = Qt::LeftButton;
QVariant other;
};
enum ExpandLinksMode {
ExpandLinksNone,
ExpandLinksShortened,
ExpandLinksAll,
ExpandLinksUrlOnly, // For custom urls leaves only url instead of text.
};
class ClickHandlerHost {
protected:
virtual void clickHandlerActiveChanged(const ClickHandlerPtr &action, bool active) {
}
virtual void clickHandlerPressedChanged(const ClickHandlerPtr &action, bool pressed) {
}
virtual ~ClickHandlerHost() = 0;
friend class ClickHandler;
};
class EntityInText;
struct TextWithEntities;
class ClickHandler {
public:
virtual ~ClickHandler() {
}
virtual void onClick(ClickContext context) const = 0;
// What text to show in a tooltip when mouse is over that click handler as a link in Text.
virtual QString tooltip() const {
return QString();
}
// What to drop in the input fields when dragging that click handler as a link from Text.
virtual QString dragText() const {
return QString();
}
// Copy to clipboard support.
virtual QString copyToClipboardText() const {
return QString();
}
virtual QString copyToClipboardContextItemText() const {
return QString();
}
// Entities in text support.
// This method returns empty string if just textPart should be used (nothing to expand).
virtual QString getExpandedLinkText(ExpandLinksMode mode, const QStringRef &textPart) const;
virtual TextWithEntities getExpandedLinkTextWithEntities(ExpandLinksMode mode, int entityOffset, const QStringRef &textPart) const;
// This method should be called on mouse over a click handler.
// It returns true if the active handler was changed or false otherwise.
static bool setActive(const ClickHandlerPtr &p, ClickHandlerHost *host = nullptr);
// This method should be called when mouse leaves the host.
// It returns true if the active handler was changed or false otherwise.
static bool clearActive(ClickHandlerHost *host = nullptr) {
if (host && _activeHost != host) {
return false;
}
return setActive(ClickHandlerPtr(), host);
}
// This method should be called on mouse press event.
static void pressed() {
unpressed();
if (!_active || !*_active) {
return;
}
_pressed.createIfNull();
*_pressed = *_active;
if ((_pressedHost = _activeHost)) {
_pressedHost->clickHandlerPressedChanged(*_pressed, true);
}
}
// This method should be called on mouse release event.
// The activated click handler (if any) is returned.
static ClickHandlerPtr unpressed() {
if (_pressed && *_pressed) {
const auto activated = (_active && *_active == *_pressed);
const auto waspressed = base::take(*_pressed);
if (_pressedHost) {
_pressedHost->clickHandlerPressedChanged(waspressed, false);
_pressedHost = nullptr;
}
if (activated) {
return *_active;
} else if (_active && *_active && _activeHost) {
// emit clickHandlerActiveChanged for current active
// click handler, which we didn't emit while we has
// a pressed click handler
_activeHost->clickHandlerActiveChanged(*_active, true);
}
}
return ClickHandlerPtr();
}
static ClickHandlerPtr getActive() {
return _active ? *_active : ClickHandlerPtr();
}
static ClickHandlerPtr getPressed() {
return _pressed ? *_pressed : ClickHandlerPtr();
}
static bool showAsActive(const ClickHandlerPtr &p) {
if (!p || !_active || p != *_active) {
return false;
}
return !_pressed || !*_pressed || (p == *_pressed);
}
static bool showAsPressed(const ClickHandlerPtr &p) {
if (!p || !_active || p != *_active) {
return false;
}
return _pressed && (p == *_pressed);
}
static void hostDestroyed(ClickHandlerHost *host) {
if (_activeHost == host) {
if (_active) {
*_active = nullptr;
}
_activeHost = nullptr;
}
if (_pressedHost == host) {
if (_pressed) {
*_pressed = nullptr;
}
_pressedHost = nullptr;
}
}
protected:
// For click handlers like mention or hashtag in getExpandedLinkTextWithEntities()
// we return just an empty string ("use original string part") with single entity.
TextWithEntities simpleTextWithEntity(const EntityInText &entity) const;
private:
static NeverFreedPointer<ClickHandlerPtr> _active;
static NeverFreedPointer<ClickHandlerPtr> _pressed;
static ClickHandlerHost *_activeHost;
static ClickHandlerHost *_pressedHost;
};
class LeftButtonClickHandler : public ClickHandler {
public:
void onClick(ClickContext context) const override final {
if (context.button == Qt::LeftButton) {
onClickImpl();
}
}
protected:
virtual void onClickImpl() const = 0;
};
class LambdaClickHandler : public ClickHandler {
public:
LambdaClickHandler(Fn<void()> handler) : _handler(std::move(handler)) {
}
void onClick(ClickContext context) const override final {
if (context.button == Qt::LeftButton && _handler) {
_handler();
}
}
private:
Fn<void()> _handler;
};