o3de/Code/Tools/CryCommonTools/UI/Layout.cpp

/*
* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
* its licensors.
*
* For complete copyright and license terms please see the LICENSE at the root of this
* distribution (the "License"). All use of this software is governed by the License,
* or, if provided, by the license below or the license accompanying this file. Do not
* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
*/
// Original file Copyright Crytek GMBH or its affiliates, used under license.

#include "StdAfx.h"
#include "Layout.h"
#include <cassert>
#include <Windows.h>

Layout::Layout(Direction direction)
    :   m_direction(direction)
{
}

void Layout::AddComponent(IUIComponent* component)
{
    m_components.push_back(ComponentEntry(component));
}

void Layout::CreateUI(void* window, int left, int top, int width, int height)
{
    UpdateLayout(window, left, top, width, height);

    for (int componentIndex = 0, componentCount = int(m_components.size()); componentIndex < componentCount; ++componentIndex)
    {
        IUIComponent* component = m_components[componentIndex].component;
        component->CreateUI(window, m_components[componentIndex].left, m_components[componentIndex].top, m_components[componentIndex].width, m_components[componentIndex].height);
    }
}

void Layout::Resize(void* window, int left, int top, int width, int height)
{
    UpdateLayout(window, left, top, width, height);

    for (int componentIndex = 0, componentCount = int(m_components.size()); componentIndex < componentCount; ++componentIndex)
    {
        IUIComponent* component = m_components[componentIndex].component;
        component->Resize(window, m_components[componentIndex].left, m_components[componentIndex].top, m_components[componentIndex].width, m_components[componentIndex].height);
    }
}

void Layout::DestroyUI(void* window)
{
    for (int componentIndex = 0, componentCount = int(m_components.size()); componentIndex < componentCount; ++componentIndex)
    {
        IUIComponent* component = m_components[componentIndex].component;
        component->DestroyUI(window);
    }
}

void Layout::GetExtremeDimensions(void* window, int& minWidth, int& maxWidth, int& minHeight, int& maxHeight)
{
    int minW = 0;
    int maxW = 0;
    int minH = 0;
    int maxH = 0;
    for (int componentIndex = 0, componentCount = int(m_components.size()); componentIndex < componentCount; ++componentIndex)
    {
        IUIComponent* component = m_components[componentIndex].component;
        int compMinW, compMaxW, compMinH, compMaxH;
        component->GetExtremeDimensions(window, compMinW, compMaxW, compMinH, compMaxH);
        switch (m_direction)
        {
        case DirectionVertical:
            minW = (minW > compMinW ? minW : compMinW);
            maxW = (maxW > compMaxW ? maxW : compMaxW); // Deliberately take the larger maximum.
            minH += compMinH;
            maxH += compMaxH;
            break;
        case DirectionHorizontal:
            minW += compMinW;
            maxW += compMaxW;
            minH = (minH > compMinH ? minH : compMinH);
            maxH = (maxH > compMaxH ? maxH : compMaxH); // Deliberately take the larger maximum.
            break;
        }
    }

    // Make sure the window is at least a certain size;
    minW = (minW >= 10 ? minW : 10);
    maxW = (maxW >= minW ? maxW : minW);
    minH = (minH >= 10 ? minH : 10);
    maxH = (maxH >= minH ? maxH : minH);

    minWidth = minW;
    maxWidth = maxW;
    minHeight = minH;
    maxHeight = maxH;
}

void Layout::UpdateLayout(void* window, int left, int top, int width, int height)
{
    assert(window);

    int remainingToAllocate;
    switch (m_direction)
    {
    case DirectionVertical:
        remainingToAllocate = height;
        break;
    case DirectionHorizontal:
        remainingToAllocate = width;
        break;
    }

    int smallestAllocationAmount = INT_MAX;
    int canBeExtendedCount = 0;
    for (int componentIndex = 0, componentCount = int(m_components.size()); componentIndex < componentCount; ++componentIndex)
    {
        IUIComponent* component = m_components[componentIndex].component;
        int compMinW, compMaxW, compMinH, compMaxH;
        component->GetExtremeDimensions(window, compMinW, compMaxW, compMinH, compMaxH);

        switch (m_direction)
        {
        case DirectionVertical:
        {
            int allocationAmount = compMaxH - compMinH;
            if (allocationAmount > 0)
            {
                ++canBeExtendedCount;
                smallestAllocationAmount = (smallestAllocationAmount < allocationAmount ? smallestAllocationAmount : allocationAmount);
            }
            m_components[componentIndex].height = compMinH;
            m_components[componentIndex].width = (width > compMaxW ? compMaxW : width);
            remainingToAllocate -= m_components[componentIndex].height;
        }
        break;

        case DirectionHorizontal:
        {
            int allocationAmount = compMaxW - compMinW;
            if (allocationAmount > 0)
            {
                ++canBeExtendedCount;
                smallestAllocationAmount = (smallestAllocationAmount < allocationAmount ? smallestAllocationAmount : allocationAmount);
            }
            m_components[componentIndex].width = compMinW;
            m_components[componentIndex].height = (height > compMaxH ? compMaxH : height);
            remainingToAllocate -= m_components[componentIndex].width;
        }
        break;
        }
    }

    while (remainingToAllocate > 0 && canBeExtendedCount > 0)
    {
        int equitablePerCompAllocation = remainingToAllocate / canBeExtendedCount;
        int compAllocation = (equitablePerCompAllocation < smallestAllocationAmount ? equitablePerCompAllocation : smallestAllocationAmount);
        compAllocation = (compAllocation > 0 ? compAllocation : 1);
        canBeExtendedCount = 0;
        smallestAllocationAmount = INT_MAX;
        for (int componentIndex = 0, componentCount = int(m_components.size()); componentIndex < componentCount; ++componentIndex)
        {
            IUIComponent* component = m_components[componentIndex].component;
            int compMinW, compMaxW, compMinH, compMaxH;
            component->GetExtremeDimensions(window, compMinW, compMaxW, compMinH, compMaxH);
            switch (m_direction)
            {
            case DirectionVertical:
            {
                int componentExpandAmount = compMaxH - m_components[componentIndex].height;
                if (componentExpandAmount > 0)
                {
                    m_components[componentIndex].height += compAllocation;
                    assert(m_components[componentIndex].height <= compMaxH);
                    componentExpandAmount -= compAllocation;
                    remainingToAllocate -= compAllocation;
                    if (componentExpandAmount > 0)
                    {
                        smallestAllocationAmount = (smallestAllocationAmount < componentExpandAmount ? smallestAllocationAmount : componentExpandAmount);
                        ++canBeExtendedCount;
                    }
                }
            }
            break;

            case DirectionHorizontal:
            {
                int componentExpandAmount = compMaxW - m_components[componentIndex].width;
                if (componentExpandAmount > 0)
                {
                    m_components[componentIndex].width += compAllocation;
                    assert(m_components[componentIndex].width <= compMaxW);
                    componentExpandAmount -= compAllocation;
                    remainingToAllocate -= compAllocation;
                    if (componentExpandAmount > 0)
                    {
                        smallestAllocationAmount = (smallestAllocationAmount < componentExpandAmount ? smallestAllocationAmount : componentExpandAmount);
                        ++canBeExtendedCount;
                    }
                }
            }
            break;
            }
        }
    }

    switch (m_direction)
    {
    case DirectionVertical:
    {
        int posY = top;
        for (int componentIndex = 0, componentCount = int(m_components.size()); componentIndex < componentCount; ++componentIndex)
        {
            m_components[componentIndex].left = left;
            m_components[componentIndex].top = posY;
            posY += m_components[componentIndex].height;
        }
    }
    break;
    case DirectionHorizontal:
    {
        int posX = left;
        for (int componentIndex = 0, componentCount = int(m_components.size()); componentIndex < componentCount; ++componentIndex)
        {
            m_components[componentIndex].top = top;
            m_components[componentIndex].left = posX;
            posX += m_components[componentIndex].width;
        }
    }
    break;
    }
}