zoom.cpp

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/*
    KWin - the KDE window manager
    This file is part of the KDE project.
 
    SPDX-FileCopyrightText: 2006 Lubos Lunak <l.lunak@kde.org>
    SPDX-FileCopyrightText: 2010 Sebastian Sauer <sebsauer@kdab.com>
 
    SPDX-License-Identifier: GPL-2.0-or-later
*/
 
#include "zoom.h"
// KConfigSkeleton
#include "zoomconfig.h"
 
#if HAVE_ACCESSIBILITY
#include "accessibilityintegration.h"
#endif
 
#include <KConfigGroup>
#include <KGlobalAccel>
#include <KLocalizedString>
#include <QAction>
#include <QStyle>
#include <QVector2D>
#include <kstandardaction.h>
 
#include "core/rendertarget.h"
#include "core/renderviewport.h"
#include "effect/effecthandler.h"
#include "opengl/glutils.h"
 
namespace KWin
{
 
ZoomEffect::ZoomEffect()
    : Effect()
    , zoom(1)
    , target_zoom(1)
    , polling(false)
    , zoomFactor(1.25)
    , mouseTracking(MouseTrackingProportional)
    , mousePointer(MousePointerScale)
    , focusDelay(350) // in milliseconds
    , isMouseHidden(false)
    , xMove(0)
    , yMove(0)
    , moveFactor(20.0)
    , lastPresentTime(std::chrono::milliseconds::zero())
{
    ZoomConfig::instance(effects->config());
    QAction *a = nullptr;
    a = KStandardAction::zoomIn(this, SLOT(zoomIn()), this);
    KGlobalAccel::self()->setDefaultShortcut(a, QList<QKeySequence>() << (Qt::META | Qt::Key_Plus) << (Qt::META | Qt::Key_Equal));
    KGlobalAccel::self()->setShortcut(a, QList<QKeySequence>() << (Qt::META | Qt::Key_Plus) << (Qt::META | Qt::Key_Equal));
    effects->registerAxisShortcut(Qt::ControlModifier | Qt::MetaModifier, PointerAxisDown, a);
 
    a = KStandardAction::zoomOut(this, SLOT(zoomOut()), this);
    KGlobalAccel::self()->setDefaultShortcut(a, QList<QKeySequence>() << (Qt::META | Qt::Key_Minus));
    KGlobalAccel::self()->setShortcut(a, QList<QKeySequence>() << (Qt::META | Qt::Key_Minus));
    effects->registerAxisShortcut(Qt::ControlModifier | Qt::MetaModifier, PointerAxisUp, a);
 
    a = KStandardAction::actualSize(this, SLOT(actualSize()), this);
    KGlobalAccel::self()->setDefaultShortcut(a, QList<QKeySequence>() << (Qt::META | Qt::Key_0));
    KGlobalAccel::self()->setShortcut(a, QList<QKeySequence>() << (Qt::META | Qt::Key_0));
 
    a = new QAction(this);
    a->setObjectName(QStringLiteral("MoveZoomLeft"));
    a->setText(i18n("Move Zoomed Area to Left"));
    KGlobalAccel::self()->setDefaultShortcut(a, QList<QKeySequence>());
    KGlobalAccel::self()->setShortcut(a, QList<QKeySequence>());
    connect(a, &QAction::triggered, this, &ZoomEffect::moveZoomLeft);
 
    a = new QAction(this);
    a->setObjectName(QStringLiteral("MoveZoomRight"));
    a->setText(i18n("Move Zoomed Area to Right"));
    KGlobalAccel::self()->setDefaultShortcut(a, QList<QKeySequence>());
    KGlobalAccel::self()->setShortcut(a, QList<QKeySequence>());
    connect(a, &QAction::triggered, this, &ZoomEffect::moveZoomRight);
 
    a = new QAction(this);
    a->setObjectName(QStringLiteral("MoveZoomUp"));
    a->setText(i18n("Move Zoomed Area Upwards"));
    KGlobalAccel::self()->setDefaultShortcut(a, QList<QKeySequence>());
    KGlobalAccel::self()->setShortcut(a, QList<QKeySequence>());
    connect(a, &QAction::triggered, this, &ZoomEffect::moveZoomUp);
 
    a = new QAction(this);
    a->setObjectName(QStringLiteral("MoveZoomDown"));
    a->setText(i18n("Move Zoomed Area Downwards"));
    KGlobalAccel::self()->setDefaultShortcut(a, QList<QKeySequence>());
    KGlobalAccel::self()->setShortcut(a, QList<QKeySequence>());
    connect(a, &QAction::triggered, this, &ZoomEffect::moveZoomDown);
 
    // TODO: these two actions don't belong into the effect. They need to be moved into KWin core
    a = new QAction(this);
    a->setObjectName(QStringLiteral("MoveMouseToFocus"));
    a->setText(i18n("Move Mouse to Focus"));
    KGlobalAccel::self()->setDefaultShortcut(a, QList<QKeySequence>() << (Qt::META | Qt::Key_F5));
    KGlobalAccel::self()->setShortcut(a, QList<QKeySequence>() << (Qt::META | Qt::Key_F5));
    connect(a, &QAction::triggered, this, &ZoomEffect::moveMouseToFocus);
 
    a = new QAction(this);
    a->setObjectName(QStringLiteral("MoveMouseToCenter"));
    a->setText(i18n("Move Mouse to Center"));
    KGlobalAccel::self()->setDefaultShortcut(a, QList<QKeySequence>() << (Qt::META | Qt::Key_F6));
    KGlobalAccel::self()->setShortcut(a, QList<QKeySequence>() << (Qt::META | Qt::Key_F6));
    connect(a, &QAction::triggered, this, &ZoomEffect::moveMouseToCenter);
 
    timeline.setDuration(350);
    timeline.setFrameRange(0, 100);
    connect(&timeline, &QTimeLine::frameChanged, this, &ZoomEffect::timelineFrameChanged);
    connect(effects, &EffectsHandler::mouseChanged, this, &ZoomEffect::slotMouseChanged);
    connect(effects, &EffectsHandler::windowAdded, this, &ZoomEffect::slotWindowAdded);
    connect(effects, &EffectsHandler::screenRemoved, this, &ZoomEffect::slotScreenRemoved);
 
#if HAVE_ACCESSIBILITY
    if (!effects->waylandDisplay()) {
        // on Wayland, the accessibility integration can cause KWin to hang
        m_accessibilityIntegration = new ZoomAccessibilityIntegration(this);
        connect(m_accessibilityIntegration, &ZoomAccessibilityIntegration::focusPointChanged, this, &ZoomEffect::moveFocus);
    }
#endif
 
    const auto windows = effects->stackingOrder();
    for (EffectWindow *w : windows) {
        slotWindowAdded(w);
    }
 
    source_zoom = -1; // used to trigger initialZoom reading
    reconfigure(ReconfigureAll);
}
 
ZoomEffect::~ZoomEffect()
{
    // switch off and free resources
    showCursor();
    // Save the zoom value.
    ZoomConfig::setInitialZoom(target_zoom);
    ZoomConfig::self()->save();
}
 
bool ZoomEffect::isFocusTrackingEnabled() const
{
#if HAVE_ACCESSIBILITY
    return m_accessibilityIntegration && m_accessibilityIntegration->isFocusTrackingEnabled();
#else
    return false;
#endif
}
 
bool ZoomEffect::isTextCaretTrackingEnabled() const
{
#if HAVE_ACCESSIBILITY
    return m_accessibilityIntegration && m_accessibilityIntegration->isTextCaretTrackingEnabled();
#else
    return false;
#endif
}
 
GLTexture *ZoomEffect::ensureCursorTexture()
{
    if (!m_cursorTexture || m_cursorTextureDirty) {
        m_cursorTexture.reset();
        m_cursorTextureDirty = false;
        const auto cursor = effects->cursorImage();
        if (!cursor.image().isNull()) {
            m_cursorTexture = GLTexture::upload(cursor.image());
            if (!m_cursorTexture) {
                return nullptr;
            }
            m_cursorTexture->setWrapMode(GL_CLAMP_TO_EDGE);
        }
    }
    return m_cursorTexture.get();
}
 
void ZoomEffect::markCursorTextureDirty()
{
    m_cursorTextureDirty = true;
}
 
void ZoomEffect::showCursor()
{
    if (isMouseHidden) {
        disconnect(effects, &EffectsHandler::cursorShapeChanged, this, &ZoomEffect::markCursorTextureDirty);
        // show the previously hidden mouse-pointer again and free the loaded texture/picture.
        effects->showCursor();
        m_cursorTexture.reset();
        isMouseHidden = false;
    }
}
 
void ZoomEffect::hideCursor()
{
    if (mouseTracking == MouseTrackingProportional && mousePointer == MousePointerKeep) {
        return; // don't replace the actual cursor by a static image for no reason.
    }
    if (!isMouseHidden) {
        // try to load the cursor-theme into a OpenGL texture and if successful then hide the mouse-pointer
        GLTexture *texture = nullptr;
        if (effects->isOpenGLCompositing()) {
            texture = ensureCursorTexture();
        }
        if (texture) {
            effects->hideCursor();
            connect(effects, &EffectsHandler::cursorShapeChanged, this, &ZoomEffect::markCursorTextureDirty);
            isMouseHidden = true;
        }
    }
}
 
void ZoomEffect::reconfigure(ReconfigureFlags)
{
    ZoomConfig::self()->read();
    // On zoom-in and zoom-out change the zoom by the defined zoom-factor.
    zoomFactor = std::max(0.1, ZoomConfig::zoomFactor());
    // Visibility of the mouse-pointer.
    mousePointer = MousePointerType(ZoomConfig::mousePointer());
    // Track moving of the mouse.
    mouseTracking = MouseTrackingType(ZoomConfig::mouseTracking());
#if HAVE_ACCESSIBILITY
    if (m_accessibilityIntegration) {
        // Enable tracking of the focused location.
        m_accessibilityIntegration->setFocusTrackingEnabled(ZoomConfig::enableFocusTracking());
        // Enable tracking of the text caret.
        m_accessibilityIntegration->setTextCaretTrackingEnabled(ZoomConfig::enableTextCaretTracking());
    }
#endif
    // The time in milliseconds to wait before a focus-event takes away a mouse-move.
    focusDelay = std::max(uint(0), ZoomConfig::focusDelay());
    // The factor the zoom-area will be moved on touching an edge on push-mode or using the navigation KAction's.
    moveFactor = std::max(0.1, ZoomConfig::moveFactor());
    if (source_zoom < 0) {
        // Load the saved zoom value.
        source_zoom = 1.0;
        target_zoom = ZoomConfig::initialZoom();
        if (target_zoom > 1.0) {
            zoomIn(target_zoom);
        }
    } else {
        source_zoom = 1.0;
    }
}
 
void ZoomEffect::prePaintScreen(ScreenPrePaintData &data, std::chrono::milliseconds presentTime)
{
    if (zoom != target_zoom) {
        int time = 0;
        if (lastPresentTime.count()) {
            time = (presentTime - lastPresentTime).count();
        }
        lastPresentTime = presentTime;
 
        const float zoomDist = std::abs(target_zoom - source_zoom);
        if (target_zoom > zoom) {
            zoom = std::min(zoom + ((zoomDist * time) / animationTime(150 * zoomFactor)), target_zoom);
        } else {
            zoom = std::max(zoom - ((zoomDist * time) / animationTime(150 * zoomFactor)), target_zoom);
        }
    }
 
    if (zoom == 1.0) {
        showCursor();
    } else {
        hideCursor();
    }
 
    effects->prePaintScreen(data, presentTime);
}
 
ZoomEffect::OffscreenData *ZoomEffect::ensureOffscreenData(const RenderTarget &renderTarget, const RenderViewport &viewport, Output *screen)
{
    const QRect rect = viewport.renderRect().toRect();
    const qreal devicePixelRatio = viewport.scale();
    const QSize nativeSize = (viewport.renderRect().size() * devicePixelRatio).toSize();
 
    OffscreenData &data = m_offscreenData[effects->waylandDisplay() ? screen : nullptr];
    data.viewport = rect;
 
    const GLenum textureFormat = renderTarget.colorDescription() == ColorDescription::sRGB ? GL_RGBA8 : GL_RGBA16F;
    if (!data.texture || data.texture->size() != nativeSize || data.texture->internalFormat() != textureFormat) {
        data.texture = GLTexture::allocate(textureFormat, nativeSize);
        if (!data.texture) {
            return nullptr;
        }
        data.texture->setFilter(GL_LINEAR);
        data.texture->setWrapMode(GL_CLAMP_TO_EDGE);
        data.framebuffer = std::make_unique<GLFramebuffer>(data.texture.get());
    }
 
    return &data;
}
 
void ZoomEffect::paintScreen(const RenderTarget &renderTarget, const RenderViewport &viewport, int mask, const QRegion &region, Output *screen)
{
    OffscreenData *offscreenData = ensureOffscreenData(renderTarget, viewport, screen);
    if (!offscreenData) {
        return;
    }
 
    // Render the scene in an offscreen texture and then upscale it.
    RenderTarget offscreenRenderTarget(offscreenData->framebuffer.get(), renderTarget.colorDescription());
    RenderViewport offscreenViewport(viewport.renderRect(), viewport.scale(), offscreenRenderTarget);
    GLFramebuffer::pushFramebuffer(offscreenData->framebuffer.get());
    effects->paintScreen(offscreenRenderTarget, offscreenViewport, mask, region, screen);
    GLFramebuffer::popFramebuffer();
 
    const QSize screenSize = effects->virtualScreenSize();
    const auto scale = viewport.scale();
 
    // mouse-tracking allows navigation of the zoom-area using the mouse.
    qreal xTranslation = 0;
    qreal yTranslation = 0;
    switch (mouseTracking) {
    case MouseTrackingProportional:
        xTranslation = -int(cursorPoint.x() * (zoom - 1.0));
        yTranslation = -int(cursorPoint.y() * (zoom - 1.0));
        prevPoint = cursorPoint;
        break;
    case MouseTrackingCentred:
        prevPoint = cursorPoint;
        // fall through
    case MouseTrackingDisabled:
        xTranslation = std::min(0, std::max(int(screenSize.width() - screenSize.width() * zoom), int(screenSize.width() / 2 - prevPoint.x() * zoom)));
        yTranslation = std::min(0, std::max(int(screenSize.height() - screenSize.height() * zoom), int(screenSize.height() / 2 - prevPoint.y() * zoom)));
        break;
    case MouseTrackingPush: {
        // touching an edge of the screen moves the zoom-area in that direction.
        int x = cursorPoint.x() * zoom - prevPoint.x() * (zoom - 1.0);
        int y = cursorPoint.y() * zoom - prevPoint.y() * (zoom - 1.0);
        int threshold = 4;
        xMove = yMove = 0;
        if (x < threshold) {
            xMove = (x - threshold) / zoom;
        } else if (x + threshold > screenSize.width()) {
            xMove = (x + threshold - screenSize.width()) / zoom;
        }
        if (y < threshold) {
            yMove = (y - threshold) / zoom;
        } else if (y + threshold > screenSize.height()) {
            yMove = (y + threshold - screenSize.height()) / zoom;
        }
        if (xMove) {
            prevPoint.setX(std::max(0, std::min(screenSize.width(), prevPoint.x() + xMove)));
        }
        if (yMove) {
            prevPoint.setY(std::max(0, std::min(screenSize.height(), prevPoint.y() + yMove)));
        }
        xTranslation = -int(prevPoint.x() * (zoom - 1.0));
        yTranslation = -int(prevPoint.y() * (zoom - 1.0));
        break;
    }
    }
 
    // use the focusPoint if focus tracking is enabled
    if (isFocusTrackingEnabled() || isTextCaretTrackingEnabled()) {
        bool acceptFocus = true;
        if (mouseTracking != MouseTrackingDisabled && focusDelay > 0) {
            // Wait some time for the mouse before doing the switch. This serves as threshold
            // to prevent the focus from jumping around to much while working with the mouse.
            const int msecs = lastMouseEvent.msecsTo(lastFocusEvent);
            acceptFocus = msecs > focusDelay;
        }
        if (acceptFocus) {
            xTranslation = -int(focusPoint.x() * (zoom - 1.0));
            yTranslation = -int(focusPoint.y() * (zoom - 1.0));
            prevPoint = focusPoint;
        }
    }
 
    // Render transformed offscreen texture.
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glClear(GL_COLOR_BUFFER_BIT);
 
    auto shader = ShaderManager::instance()->pushShader(ShaderTrait::MapTexture);
    for (auto &[screen, offscreen] : m_offscreenData) {
        QMatrix4x4 matrix;
        matrix.translate(xTranslation * scale, yTranslation * scale);
        matrix.scale(zoom, zoom);
        matrix.translate(offscreen.viewport.x() * scale, offscreen.viewport.y() * scale);
 
        shader->setUniform(GLShader::Mat4Uniform::ModelViewProjectionMatrix, viewport.projectionMatrix() * matrix);
 
        offscreen.texture->render(offscreen.viewport.size() * scale);
    }
    ShaderManager::instance()->popShader();
 
    if (mousePointer != MousePointerHide) {
        // Draw the mouse-texture at the position matching to zoomed-in image of the desktop. Hiding the
        // previous mouse-cursor and drawing our own fake mouse-cursor is needed to be able to scale the
        // mouse-cursor up and to re-position those mouse-cursor to match to the chosen zoom-level.
 
        GLTexture *cursorTexture = ensureCursorTexture();
        if (cursorTexture) {
            const auto cursor = effects->cursorImage();
            QSizeF cursorSize = QSizeF(cursor.image().size()) / cursor.image().devicePixelRatio();
            if (mousePointer == MousePointerScale) {
                cursorSize *= zoom;
            }
 
            const QPointF p = (effects->cursorPos() - cursor.hotSpot()) * zoom + QPoint(xTranslation, yTranslation);
 
            glEnable(GL_BLEND);
            glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
            auto s = ShaderManager::instance()->pushShader(ShaderTrait::MapTexture | ShaderTrait::TransformColorspace);
            s->setColorspaceUniformsFromSRGB(renderTarget.colorDescription());
            QMatrix4x4 mvp = viewport.projectionMatrix();
            mvp.translate(p.x() * scale, p.y() * scale);
            s->setUniform(GLShader::Mat4Uniform::ModelViewProjectionMatrix, mvp);
            cursorTexture->render(cursorSize * scale);
            ShaderManager::instance()->popShader();
            glDisable(GL_BLEND);
        }
    }
}
 
void ZoomEffect::postPaintScreen()
{
    if (zoom == target_zoom) {
        lastPresentTime = std::chrono::milliseconds::zero();
    }
 
    if (zoom == 1.0 || zoom != target_zoom) {
        // Either animation is running or the zoom effect has stopped.
        effects->addRepaintFull();
    }
 
    effects->postPaintScreen();
}
 
void ZoomEffect::zoomIn(double to)
{
    source_zoom = zoom;
    if (to < 0.0) {
        target_zoom *= zoomFactor;
    } else {
        target_zoom = to;
    }
    if (!polling) {
        polling = true;
        effects->startMousePolling();
    }
    cursorPoint = effects->cursorPos().toPoint();
    if (mouseTracking == MouseTrackingDisabled) {
        prevPoint = cursorPoint;
    }
    effects->addRepaintFull();
}
 
void ZoomEffect::zoomOut()
{
    source_zoom = zoom;
    target_zoom /= zoomFactor;
    if ((zoomFactor > 1 && target_zoom < 1.01) || (zoomFactor < 1 && target_zoom > 0.99)) {
        target_zoom = 1;
        if (polling) {
            polling = false;
            effects->stopMousePolling();
        }
    }
    if (mouseTracking == MouseTrackingDisabled) {
        prevPoint = effects->cursorPos().toPoint();
    }
    effects->addRepaintFull();
}
 
void ZoomEffect::actualSize()
{
    source_zoom = zoom;
    target_zoom = 1;
    if (polling) {
        polling = false;
        effects->stopMousePolling();
    }
    effects->addRepaintFull();
}
 
void ZoomEffect::timelineFrameChanged(int /* frame */)
{
    const QSize screenSize = effects->virtualScreenSize();
    prevPoint.setX(std::max(0, std::min(screenSize.width(), prevPoint.x() + xMove)));
    prevPoint.setY(std::max(0, std::min(screenSize.height(), prevPoint.y() + yMove)));
    cursorPoint = prevPoint;
    effects->addRepaintFull();
}
 
void ZoomEffect::moveZoom(int x, int y)
{
    if (timeline.state() == QTimeLine::Running) {
        timeline.stop();
    }
 
    const QSize screenSize = effects->virtualScreenSize();
    if (x < 0) {
        xMove = -std::max(1.0, screenSize.width() / zoom / moveFactor);
    } else if (x > 0) {
        xMove = std::max(1.0, screenSize.width() / zoom / moveFactor);
    } else {
        xMove = 0;
    }
 
    if (y < 0) {
        yMove = -std::max(1.0, screenSize.height() / zoom / moveFactor);
    } else if (y > 0) {
        yMove = std::max(1.0, screenSize.height() / zoom / moveFactor);
    } else {
        yMove = 0;
    }
 
    timeline.start();
}
 
void ZoomEffect::moveZoomLeft()
{
    moveZoom(-1, 0);
}
 
void ZoomEffect::moveZoomRight()
{
    moveZoom(1, 0);
}
 
void ZoomEffect::moveZoomUp()
{
    moveZoom(0, -1);
}
 
void ZoomEffect::moveZoomDown()
{
    moveZoom(0, 1);
}
 
void ZoomEffect::moveMouseToFocus()
{
    QCursor::setPos(focusPoint.x(), focusPoint.y());
}
 
void ZoomEffect::moveMouseToCenter()
{
    const QRect r = effects->virtualScreenGeometry();
    QCursor::setPos(r.x() + r.width() / 2, r.y() + r.height() / 2);
}
 
void ZoomEffect::slotMouseChanged(const QPointF &pos, const QPointF &old, Qt::MouseButtons,
                                  Qt::MouseButtons, Qt::KeyboardModifiers, Qt::KeyboardModifiers)
{
    if (zoom == 1.0) {
        return;
    }
    cursorPoint = pos.toPoint();
    if (pos != old) {
        lastMouseEvent = QTime::currentTime();
        effects->addRepaintFull();
    }
}
 
void ZoomEffect::slotWindowAdded(EffectWindow *w)
{
    connect(w, &EffectWindow::windowDamaged, this, &ZoomEffect::slotWindowDamaged);
}
 
void ZoomEffect::slotWindowDamaged()
{
    if (zoom != 1.0) {
        effects->addRepaintFull();
    }
}
 
void ZoomEffect::slotScreenRemoved(Output *screen)
{
    if (auto it = m_offscreenData.find(screen); it != m_offscreenData.end()) {
        effects->makeOpenGLContextCurrent();
        m_offscreenData.erase(it);
    }
}
 
void ZoomEffect::moveFocus(const QPoint &point)
{
    if (zoom == 1.0) {
        return;
    }
    focusPoint = point;
    lastFocusEvent = QTime::currentTime();
    effects->addRepaintFull();
}
 
bool ZoomEffect::isActive() const
{
    return zoom != 1.0 || zoom != target_zoom;
}
 
int ZoomEffect::requestedEffectChainPosition() const
{
    return 10;
}
 
qreal ZoomEffect::configuredZoomFactor() const
{
    return zoomFactor;
}
 
int ZoomEffect::configuredMousePointer() const
{
    return mousePointer;
}
 
int ZoomEffect::configuredMouseTracking() const
{
    return mouseTracking;
}
 
int ZoomEffect::configuredFocusDelay() const
{
    return focusDelay;
}
 
qreal ZoomEffect::configuredMoveFactor() const
{
    return moveFactor;
}
 
qreal ZoomEffect::targetZoom() const
{
    return target_zoom;
}
 
} // namespace
 
#include "moc_zoom.cpp"