gestures: add scroll_move (#14063)

2 files changed, 172 insertions, 0 deletions

diff --git a/src/managers/input/trackpad/gestures/ScrollMoveGesture.cpp b/src/managers/input/trackpad/gestures/ScrollMoveGesture.cpp
new file mode 100644
index 00000000..032bf679
--- /dev/null
+++ b/src/managers/input/trackpad/gestures/ScrollMoveGesture.cpp
@@ -0,0 +1,145 @@
+#include "ScrollMoveGesture.hpp"
+
+#include "../../../../desktop/state/FocusState.hpp"
+#include "../../../../desktop/Workspace.hpp"
+#include "../../../../helpers/Monitor.hpp"
+#include "../../../../layout/LayoutManager.hpp"
+#include "../../../../layout/algorithm/Algorithm.hpp"
+#include "../../../../layout/algorithm/tiled/scrolling/ScrollingAlgorithm.hpp"
+#include "../../../../layout/space/Space.hpp"
+#include "../../../../config/ConfigValue.hpp"
+#include "../../../../Compositor.hpp"
+
+#include <algorithm>
+#include <cmath>
+
+constexpr double                           SCROLL_GESTURE_VELOCITY_DECAY  = 4.0;
+constexpr double                           SCROLL_GESTURE_MAX_PROJECTION  = 2.0;
+constexpr double                           SCROLL_GESTURE_VELOCITY_SMOOTH = 0.35;
+
+static Layout::Tiled::CScrollingAlgorithm* currentScrollingLayout() {
+    const auto PMONITOR = Desktop::focusState()->monitor();
+    if (!PMONITOR)
+        return nullptr;
+
+    const auto PWORKSPACE = PMONITOR->m_activeSpecialWorkspace ? PMONITOR->m_activeSpecialWorkspace : PMONITOR->m_activeWorkspace;
+    if (!PWORKSPACE || !PWORKSPACE->m_space)
+        return nullptr;
+
+    const auto ALGORITHM = PWORKSPACE->m_space->algorithm();
+    if (!ALGORITHM || !ALGORITHM->tiledAlgo())
+        return nullptr;
+
+    return dynamic_cast<Layout::Tiled::CScrollingAlgorithm*>(ALGORITHM->tiledAlgo().get());
+}
+
+static float deltaForUpdate(const ITrackpadGesture::STrackpadGestureUpdate& e) {
+    if (!e.swipe)
+        return 0.F;
+
+    switch (e.direction) {
+        case TRACKPAD_GESTURE_DIR_LEFT:
+        case TRACKPAD_GESTURE_DIR_RIGHT:
+        case TRACKPAD_GESTURE_DIR_HORIZONTAL: return e.swipe->delta.x * e.scale;
+        case TRACKPAD_GESTURE_DIR_UP:
+        case TRACKPAD_GESTURE_DIR_DOWN:
+        case TRACKPAD_GESTURE_DIR_VERTICAL: return e.swipe->delta.y * e.scale;
+        default: return std::abs(e.swipe->delta.x) > std::abs(e.swipe->delta.y) ? e.swipe->delta.x * e.scale : e.swipe->delta.y * e.scale;
+    }
+}
+
+void CScrollMoveTrackpadGesture::begin(const ITrackpadGesture::STrackpadGestureBegin& e) {
+    ITrackpadGesture::begin(e);
+
+    const auto LAYOUT = currentScrollingLayout();
+
+    m_wasScrollingLayout = !!LAYOUT;
+    m_hasLastUpdate      = false;
+    m_lastUpdateTimeMs   = 0;
+    m_velocity           = 0.0;
+
+    m_startedOffset = LAYOUT ? LAYOUT->normalizedTapeOffset() : 0.0;
+    m_startedColumn = LAYOUT ? LAYOUT->currentColumn() : nullptr;
+}
+
+void CScrollMoveTrackpadGesture::update(const ITrackpadGesture::STrackpadGestureUpdate& e) {
+    if (!m_wasScrollingLayout)
+        return;
+
+    const auto SCROLLING = currentScrollingLayout();
+    if (!SCROLLING)
+        return;
+
+    const float  DELTA   = deltaForUpdate(e);
+    const double PRIMARY = SCROLLING->primaryViewportSize();
+
+    if (DELTA == 0.F || PRIMARY <= 0.0)
+        return;
+
+    const double NORMALIZED_DELTA        = DELTA / PRIMARY;
+    const double NORMALIZED_OFFSET_DELTA = -NORMALIZED_DELTA;
+
+    SCROLLING->moveTapeNormalized(NORMALIZED_DELTA);
+
+    if (!e.swipe)
+        return;
+
+    if (m_hasLastUpdate && e.swipe->timeMs > m_lastUpdateTimeMs) {
+        const double DT = (e.swipe->timeMs - m_lastUpdateTimeMs) / 1000.0;
+
+        if (DT > 0.0) {
+            const double INSTANT_VELOCITY = NORMALIZED_OFFSET_DELTA / DT;
+
+            if (std::isfinite(INSTANT_VELOCITY))
+                m_velocity = m_velocity * (1.0 - SCROLL_GESTURE_VELOCITY_SMOOTH) + INSTANT_VELOCITY * SCROLL_GESTURE_VELOCITY_SMOOTH;
+        }
+    }
+
+    m_hasLastUpdate    = true;
+    m_lastUpdateTimeMs = e.swipe->timeMs;
+}
+
+void CScrollMoveTrackpadGesture::end(const ITrackpadGesture::STrackpadGestureEnd& e) {
+    static auto PSNAP       = CConfigValue<Config::BOOL>("gestures:scrolling:move_snap_to_grid");
+    static auto PSNAPCURSOR = CConfigValue<Config::BOOL>("gestures:scrolling:move_snap_cursor");
+
+    const auto  SCROLLING = currentScrollingLayout();
+    if (!m_wasScrollingLayout || !SCROLLING) {
+        m_wasScrollingLayout = false;
+        m_hasLastUpdate      = false;
+        m_velocity           = 0.0;
+        return;
+    }
+
+    const auto   CURRENT_FOCUS = Desktop::focusState()->window();
+
+    const bool   CANCELLED = e.swipe && e.swipe->cancelled;
+    const double Δ         = (CANCELLED ? 0.0 : std::clamp(m_velocity / SCROLL_GESTURE_VELOCITY_DECAY, -SCROLL_GESTURE_MAX_PROJECTION, SCROLL_GESTURE_MAX_PROJECTION));
+    const double PROJECTED = SCROLLING->normalizedTapeOffset() + Δ;
+
+    if (*PSNAP) {
+        const auto LANDED = SCROLLING->snapToProjectedOffset(PROJECTED);
+
+        // if we land on the same thing we started, move the tape back
+        if (LANDED == m_startedColumn && LANDED)
+            SCROLLING->moveTapeNormalized(SCROLLING->normalizedTapeOffset() - m_startedOffset);
+        else
+            SCROLLING->focusColumn(LANDED);
+    } else {
+        SCROLLING->moveTape(Δ);
+        const auto COL = SCROLLING->getColumnAtViewportCenter();
+        if (!COL->targetDatas.empty() && COL->targetDatas.front()->target) {
+            if (const auto W = COL->targetDatas.front()->target->window(); W)
+                Desktop::focusState()->fullWindowFocus(W, Desktop::FOCUS_REASON_FFM);
+        }
+    }
+
+    const auto NEW_FOCUS = Desktop::focusState()->window();
+
+    if (*PSNAPCURSOR && CURRENT_FOCUS != NEW_FOCUS && NEW_FOCUS)
+        g_pCompositor->warpCursorTo(NEW_FOCUS->middle());
+
+    m_wasScrollingLayout = false;
+    m_hasLastUpdate      = false;
+    m_velocity           = 0.0;
+}
diff --git a/src/managers/input/trackpad/gestures/ScrollMoveGesture.hpp b/src/managers/input/trackpad/gestures/ScrollMoveGesture.hpp
new file mode 100644
index 00000000..26e51e00
--- /dev/null
+++ b/src/managers/input/trackpad/gestures/ScrollMoveGesture.hpp
@@ -0,0 +1,27 @@
+#pragma once
+
+#include "ITrackpadGesture.hpp"
+
+#include <cstdint>
+
+namespace Layout::Tiled {
+    struct SColumnData;
+}
+
+class CScrollMoveTrackpadGesture : public ITrackpadGesture {
+  public:
+    CScrollMoveTrackpadGesture()          = default;
+    virtual ~CScrollMoveTrackpadGesture() = default;
+
+    virtual void begin(const ITrackpadGesture::STrackpadGestureBegin& e);
+    virtual void update(const ITrackpadGesture::STrackpadGestureUpdate& e);
+    virtual void end(const ITrackpadGesture::STrackpadGestureEnd& e);
+
+  private:
+    bool                           m_wasScrollingLayout = false;
+    bool                           m_hasLastUpdate      = false;
+    uint32_t                       m_lastUpdateTimeMs   = 0;
+    double                         m_velocity           = 0.0;
+    double                         m_startedOffset      = 0.0;
+    WP<Layout::Tiled::SColumnData> m_startedColumn      = nullptr;
+};