slideshow/source/engine/screenupdater.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #include <screenupdater.hxx>
  21 #include <listenercontainer.hxx>
  22
  23 #include <osl/diagnose.h>
  24
  25 #include <functional>
  26 #include <memory>
  27 #include <vector>
  28 #include <algorithm>
  29
  30 namespace {
  31     class UpdateLock : public ::slideshow::internal::ScreenUpdater::UpdateLock
  32     {
  33     public:
  34         explicit UpdateLock (::slideshow::internal::ScreenUpdater& rUpdater);
  35         virtual ~UpdateLock();
  36         virtual void Activate() override;
  37     private:
  38         ::slideshow::internal::ScreenUpdater& mrUpdater;
  39         bool mbIsActivated;
  40     };
  41 }
  42
  43 namespace slideshow
  44 {
  45 namespace internal
  46 {
  47     typedef std::vector<
  48         std::pair<UnoViewSharedPtr,bool> > UpdateRequestVector;
  49
  50     struct ScreenUpdater::ImplScreenUpdater
  51     {
  52         /** List of registered ViewUpdaters, to consult for necessary
  53             updates
  54         */
  55         ThreadUnsafeListenerContainer<
  56             ViewUpdateSharedPtr,
  57             std::vector<ViewUpdateSharedPtr> > maUpdaters;
  58
  59         /// Views that have been notified for update
  60         UpdateRequestVector                    maViewUpdateRequests;
  61
  62         /// List of View. Used to issue screen updates on.
  63         UnoViewContainer const&                mrViewContainer;
  64
  65         /// True, if a notifyUpdate() for all views has been issued.
  66         bool                                   mbUpdateAllRequest;
  67
  68         /// True, if at least one notifyUpdate() call had bViewClobbered set
  69         bool                                   mbViewClobbered;
  70
  71         /// The screen is updated only when mnLockCount==0
  72         sal_Int32 mnLockCount;
  73
  74         explicit ImplScreenUpdater( UnoViewContainer const& rViewContainer ) :
  75             maUpdaters(),
  76             maViewUpdateRequests(),
  77             mrViewContainer(rViewContainer),
  78             mbUpdateAllRequest(false),
  79             mbViewClobbered(false),
  80             mnLockCount(0)
  81         {}
  82     };
  83
  84     ScreenUpdater::ScreenUpdater( UnoViewContainer const& rViewContainer ) :
  85         mpImpl(new ImplScreenUpdater(rViewContainer) )
  86     {
  87     }
  88
  89     ScreenUpdater::~ScreenUpdater()
  90     {
  91         // outline because of pimpl
  92     }
  93
  94     void ScreenUpdater::notifyUpdate()
  95     {
  96         mpImpl->mbUpdateAllRequest = true;
  97     }
  98
  99     void ScreenUpdater::notifyUpdate( const UnoViewSharedPtr& rView,
 100                                       bool                    bViewClobbered )
 101     {
 102         mpImpl->maViewUpdateRequests.emplace_back(rView, bViewClobbered );
 103
 104         if( bViewClobbered )
 105             mpImpl->mbViewClobbered = true;
 106     }
 107
 108     void ScreenUpdater::commitUpdates()
 109     {
 110         if (mpImpl->mnLockCount > 0)
 111             return;
 112
 113         // cases:
 114
 115         // (a) no update necessary at all
 116
 117         // (b) no ViewUpdate-generated update
 118         //     I. update all views requested -> for_each( mrViewContainer )
 119         //    II. update some views requested -> for_each( maViewUpdateRequests )
 120
 121         // (c) ViewUpdate-triggered update - update all views
 122
 123
 124         // any ViewUpdate-triggered updates?
 125         const bool bViewUpdatesNeeded(
 126             mpImpl->maUpdaters.apply(
 127                 std::mem_fn(&ViewUpdate::needsUpdate)) );
 128
 129         if( bViewUpdatesNeeded )
 130         {
 131             mpImpl->maUpdaters.applyAll(
 132                 std::mem_fn((bool (ViewUpdate::*)())&ViewUpdate::update) );
 133         }
 134
 135         if( bViewUpdatesNeeded ||
 136             mpImpl->mbUpdateAllRequest )
 137         {
 138             // unconditionally update all views
 139             for( const auto& pView : mpImpl->mrViewContainer )
 140             {
 141                 if( mpImpl->mbViewClobbered )
 142                     pView->paintScreen();
 143                 else
 144                     pView->updateScreen();
 145             }
 146         }
 147         else if( !mpImpl->maViewUpdateRequests.empty() )
 148         {
 149             // update notified views only
 150             for( const auto& rViewUpdateRequest : mpImpl->maViewUpdateRequests )
 151             {
 152                 // TODO(P1): this is O(n^2) in the number of views, if
 153                 // lots of views notify updates.
 154                 const UnoViewVector::const_iterator aEndOfViews(
 155                     mpImpl->mrViewContainer.end() );
 156                 UnoViewVector::const_iterator aFoundView;
 157                 if( (aFoundView=std::find(mpImpl->mrViewContainer.begin(),
 158                                           aEndOfViews,
 159                                           rViewUpdateRequest.first)) != aEndOfViews )
 160                 {
 161                     if( rViewUpdateRequest.second )
 162                         (*aFoundView)->paintScreen(); // force-paint
 163                     else
 164                         (*aFoundView)->updateScreen(); // update changes only
 165                 }
 166             }
 167         }
 168
 169         // done - clear requests
 170         mpImpl->mbViewClobbered = false;
 171         mpImpl->mbUpdateAllRequest = false;
 172         UpdateRequestVector().swap( mpImpl->maViewUpdateRequests );
 173     }
 174
 175     void ScreenUpdater::addViewUpdate( ViewUpdateSharedPtr const& rViewUpdate )
 176     {
 177         mpImpl->maUpdaters.add( rViewUpdate );
 178     }
 179
 180     void ScreenUpdater::removeViewUpdate( ViewUpdateSharedPtr const& rViewUpdate )
 181     {
 182         mpImpl->maUpdaters.remove( rViewUpdate );
 183     }
 184
 185     void ScreenUpdater::requestImmediateUpdate()
 186     {
 187         if (mpImpl->mnLockCount > 0)
 188             return;
 189
 190         // TODO(F2): This will interfere with other updates, since it
 191         // happens out-of-sync with main animation loop. Might cause
 192         // artifacts.
 193         for( auto const& pView : mpImpl->mrViewContainer )
 194             pView->updateScreen();
 195     }
 196
 197     void ScreenUpdater::lockUpdates()
 198     {
 199         ++mpImpl->mnLockCount;
 200         OSL_ASSERT(mpImpl->mnLockCount>0);
 201     }
 202
 203     void ScreenUpdater::unlockUpdates()
 204     {
 205         OSL_ASSERT(mpImpl->mnLockCount>0);
 206         if (mpImpl->mnLockCount > 0)
 207         {
 208             --mpImpl->mnLockCount;
 209             if (mpImpl->mnLockCount)
 210                 commitUpdates();
 211         }
 212     }
 213
 214     ::std::shared_ptr<ScreenUpdater::UpdateLock> ScreenUpdater::createLock()
 215     {
 216         return ::std::shared_ptr<ScreenUpdater::UpdateLock>(new ::UpdateLock(*this));
 217     }
 218
 219
 220 } // namespace internal
 221 } // namespace slideshow
 222
 223 namespace {
 224
 225 UpdateLock::UpdateLock (
 226     ::slideshow::internal::ScreenUpdater& rUpdater)
 227     : mrUpdater(rUpdater),
 228       mbIsActivated(false)
 229 {
 230 }
 231
 232
 233 UpdateLock::~UpdateLock()
 234 {
 235     if (mbIsActivated)
 236         mrUpdater.unlockUpdates();
 237 }
 238
 239
 240 void UpdateLock::Activate()
 241 {
 242     if ( ! mbIsActivated)
 243     {
 244         mbIsActivated = true;
 245         mrUpdater.lockUpdates();
 246     }
 247 }
 248
 249 }
 250
 251 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */