services/surfaceflinger/LayerVector.cpp

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * Licensed 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
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "LayerVector.h"
#include "Layer.h"

namespace android {

LayerVector::LayerVector(const StateSet stateSet) : mStateSet(stateSet) {}

LayerVector::LayerVector(const LayerVector& rhs, const StateSet stateSet)
      : SortedVector<sp<Layer>>(rhs), mStateSet(stateSet) {}

LayerVector::~LayerVector() = default;

// This operator override is needed to prevent mStateSet from getting copied over.
LayerVector& LayerVector::operator=(const LayerVector& rhs) {
    SortedVector::operator=(rhs);
    return *this;
}

int LayerVector::do_compare(const void* lhs, const void* rhs) const
{
    // sort layers per layer-stack, then by z-order and finally by sequence
    const auto& l = *reinterpret_cast<const sp<Layer>*>(lhs);
    const auto& r = *reinterpret_cast<const sp<Layer>*>(rhs);

    const auto& lState =
            (mStateSet == StateSet::Current) ? l->getCurrentState() : l->getDrawingState();
    const auto& rState =
            (mStateSet == StateSet::Current) ? r->getCurrentState() : r->getDrawingState();

    uint32_t ls = lState.layerStack;
    uint32_t rs = rState.layerStack;
    if (ls != rs)
        return (ls > rs) ? 1 : -1;

    int32_t lz = lState.z;
    int32_t rz = rState.z;
    if (lz != rz)
        return (lz > rz) ? 1 : -1;

    if (l->sequence == r->sequence)
        return 0;

    return (l->sequence > r->sequence) ? 1 : -1;
}

void LayerVector::traverseInZOrder(StateSet stateSet, const Visitor& visitor) const {
    for (size_t i = 0; i < size(); i++) {
        const auto& layer = (*this)[i];
        auto& state = (stateSet == StateSet::Current) ? layer->getCurrentState()
                                                      : layer->getDrawingState();
        if (state.zOrderRelativeOf != nullptr) {
            continue;
        }
        layer->traverseInZOrder(stateSet, visitor);
    }
}

void LayerVector::traverseInReverseZOrder(StateSet stateSet, const Visitor& visitor) const {
    for (auto i = static_cast<int64_t>(size()) - 1; i >= 0; i--) {
        const auto& layer = (*this)[i];
        auto& state = (stateSet == StateSet::Current) ? layer->getCurrentState()
                                                      : layer->getDrawingState();
        if (state.zOrderRelativeOf != nullptr) {
            continue;
        }
        layer->traverseInReverseZOrder(stateSet, visitor);
     }
}
} // namespace android