1 files changed, 234 insertions, 0 deletions
diff --git a/sd/source/ui/slidesorter/controller/SlsVisibleAreaManager.cxx b/sd/source/ui/slidesorter/controller/SlsVisibleAreaManager.cxx
new file mode 100644
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--- /dev/null
+++ b/sd/source/ui/slidesorter/controller/SlsVisibleAreaManager.cxx
@@ -0,0 +1,234 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <sal/config.h>
+
+#include <controller/SlsVisibleAreaManager.hxx>
+#include <controller/SlideSorterController.hxx>
+#include <controller/SlsAnimationFunction.hxx>
+#include <controller/SlsScrollBarManager.hxx>
+#include <controller/SlsCurrentSlideManager.hxx>
+#include <Window.hxx>
+#include <SlideSorter.hxx>
+#include <view/SlideSorterView.hxx>
+
+namespace sd::slidesorter::controller {
+
+namespace {
+    class VisibleAreaScroller
+    {
+    public:
+        VisibleAreaScroller (
+            SlideSorter& rSlideSorter,
+            const Point& rStart,
+            const Point& rEnd);
+        void operator() (const double nValue);
+    private:
+        SlideSorter& mrSlideSorter;
+        Point maStart;
+        const Point maEnd;
+        const ::std::function<double (double)> maAccelerationFunction;
+    };
+
+} // end of anonymous namespace
+
+VisibleAreaManager::VisibleAreaManager (SlideSorter& rSlideSorter)
+    : mrSlideSorter(rSlideSorter),
+      mbIsCurrentSlideTrackingActive(true),
+      mnDisableCount(0)
+{
+}
+
+VisibleAreaManager::~VisibleAreaManager()
+{
+}
+
+void VisibleAreaManager::ActivateCurrentSlideTracking()
+{
+    mbIsCurrentSlideTrackingActive = true;
+}
+
+void VisibleAreaManager::DeactivateCurrentSlideTracking()
+{
+    mbIsCurrentSlideTrackingActive = false;
+}
+
+void VisibleAreaManager::RequestVisible (
+    const model::SharedPageDescriptor& rpDescriptor,
+    const bool bForce)
+{
+    if (!rpDescriptor)
+        return;
+
+    if (mnDisableCount == 0)
+    {
+        maVisibleRequests.push_back(
+            mrSlideSorter.GetView().GetLayouter().GetPageObjectBox(
+                rpDescriptor->GetPageIndex(),
+                true));
+    }
+    if (bForce && ! mbIsCurrentSlideTrackingActive)
+        ActivateCurrentSlideTracking();
+    MakeVisible();
+}
+
+void VisibleAreaManager::RequestCurrentSlideVisible()
+{
+    if (mbIsCurrentSlideTrackingActive && mnDisableCount==0)
+        RequestVisible(
+            mrSlideSorter.GetController().GetCurrentSlideManager()->GetCurrentSlide());
+}
+
+void VisibleAreaManager::MakeVisible()
+{
+    if (maVisibleRequests.empty())
+        return;
+
+    sd::Window *pWindow (mrSlideSorter.GetContentWindow().get());
+    if ( ! pWindow)
+        return;
+    const Point aCurrentTopLeft (pWindow->PixelToLogic(Point(0,0)));
+
+    const ::std::optional<Point> aNewVisibleTopLeft (GetRequestedTopLeft());
+    maVisibleRequests.clear();
+    if ( ! aNewVisibleTopLeft)
+        return;
+
+    maRequestedVisibleTopLeft = *aNewVisibleTopLeft;
+    VisibleAreaScroller aAnimation(
+        mrSlideSorter,
+        aCurrentTopLeft,
+        maRequestedVisibleTopLeft);
+    // Execute the animation at its final value.
+    aAnimation(1.0);
+}
+
+::std::optional<Point> VisibleAreaManager::GetRequestedTopLeft() const
+{
+    sd::Window *pWindow (mrSlideSorter.GetContentWindow().get());
+    if ( ! pWindow)
+        return ::std::optional<Point>();
+
+    // Get the currently visible area and the model area.
+    const ::tools::Rectangle aVisibleArea (pWindow->PixelToLogic(
+        ::tools::Rectangle(
+            Point(0,0),
+            pWindow->GetOutputSizePixel())));
+    const ::tools::Rectangle aModelArea (mrSlideSorter.GetView().GetModelArea());
+
+    sal_Int32 nVisibleTop (aVisibleArea.Top());
+    const sal_Int32 nVisibleWidth (aVisibleArea.GetWidth());
+    sal_Int32 nVisibleLeft (aVisibleArea.Left());
+    const sal_Int32 nVisibleHeight (aVisibleArea.GetHeight());
+
+    // Find the longest run of boxes whose union fits into the visible area.
+    for (const auto& rBox : maVisibleRequests)
+    {
+        if (nVisibleTop+nVisibleHeight <= rBox.Bottom())
+            nVisibleTop = rBox.Bottom()-nVisibleHeight;
+        if (nVisibleTop > rBox.Top())
+            nVisibleTop = rBox.Top();
+
+        if (nVisibleLeft+nVisibleWidth <= rBox.Right())
+            nVisibleLeft = rBox.Right()-nVisibleWidth;
+        if (nVisibleLeft > rBox.Left())
+            nVisibleLeft = rBox.Left();
+
+        // Make sure the visible area does not move outside the model area.
+        if (nVisibleTop + nVisibleHeight > aModelArea.Bottom())
+            nVisibleTop = aModelArea.Bottom() - nVisibleHeight;
+        if (nVisibleTop < aModelArea.Top())
+            nVisibleTop = aModelArea.Top();
+
+        if (nVisibleLeft + nVisibleWidth > aModelArea.Right())
+            nVisibleLeft = aModelArea.Right() - nVisibleWidth;
+        if (nVisibleLeft < aModelArea.Left())
+            nVisibleLeft = aModelArea.Left();
+    }
+
+    const Point aRequestedTopLeft (nVisibleLeft, nVisibleTop);
+    if (aRequestedTopLeft == aVisibleArea.TopLeft())
+        return ::std::optional<Point>();
+    else
+        return ::std::optional<Point>(aRequestedTopLeft);
+}
+
+//===== VisibleAreaManager::TemporaryDisabler =================================
+
+VisibleAreaManager::TemporaryDisabler::TemporaryDisabler (SlideSorter const & rSlideSorter)
+    : mrVisibleAreaManager(rSlideSorter.GetController().GetVisibleAreaManager())
+{
+    ++mrVisibleAreaManager.mnDisableCount;
+}
+
+VisibleAreaManager::TemporaryDisabler::~TemporaryDisabler()
+{
+    --mrVisibleAreaManager.mnDisableCount;
+}
+
+//===== VerticalVisibleAreaScroller ===========================================
+
+namespace {
+
+const sal_Int32 gnMaxScrollDistance = 300;
+
+VisibleAreaScroller::VisibleAreaScroller (
+    SlideSorter& rSlideSorter,
+    const Point& rStart,
+    const Point& rEnd)
+    : mrSlideSorter(rSlideSorter),
+      maStart(rStart),
+      maEnd(rEnd),
+      maAccelerationFunction(
+          controller::AnimationParametricFunction(
+              controller::AnimationBezierFunction (0.1,0.6)))
+{
+    // When the distance to scroll is larger than a threshold then first
+    // jump to within this distance of the final value and start the
+    // animation from there.
+    if (std::abs(rStart.X()-rEnd.X()) > gnMaxScrollDistance)
+    {
+        if (rStart.X() < rEnd.X())
+            maStart.setX( rEnd.X()-gnMaxScrollDistance );
+        else
+            maStart.setX( rEnd.X()+gnMaxScrollDistance );
+    }
+    if (std::abs(rStart.Y()-rEnd.Y()) > gnMaxScrollDistance)
+    {
+        if (rStart.Y() < rEnd.Y())
+            maStart.setY( rEnd.Y()-gnMaxScrollDistance );
+        else
+            maStart.setY( rEnd.Y()+gnMaxScrollDistance );
+    }
+}
+
+void VisibleAreaScroller::operator() (const double nTime)
+{
+    const double nLocalTime (maAccelerationFunction(nTime));
+    mrSlideSorter.GetController().GetScrollBarManager().SetTopLeft(
+        Point(
+            sal_Int32(0.5 + maStart.X() * (1.0 - nLocalTime) + maEnd.X() * nLocalTime),
+            sal_Int32 (0.5 + maStart.Y() * (1.0 - nLocalTime) + maEnd.Y() * nLocalTime)));
+}
+
+} // end of anonymous namespace
+
+} // end of namespace ::sd::slidesorter::controller
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */