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** Copyright (C) 2016 The Qt Company Ltd.
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#include "modemanager.h"

#include "fancytabwidget.h"
#include "fancyactionbar.h"
#include "icore.h"
#include "mainwindow.h"

#include <coreplugin/actionmanager/actionmanager.h>
#include <coreplugin/actionmanager/command.h>
#include <coreplugin/coreconstants.h>
#include <coreplugin/imode.h>

#include <extensionsystem/pluginmanager.h>

#include <utils/algorithm.h>
#include <utils/qtcassert.h>

#include <QAction>
#include <QDebug>
#include <QMap>
#include <QMouseEvent>
#include <QVector>

namespace Core {

/*!
    \class Core::ModeManager

    The mode manager handles everything related to the instances of IMode
    that were added to the plugin manager's object pool as well as their
    buttons and the tool bar with the round buttons in the lower left
    corner of Qt Creator.
*/

struct ModeManagerPrivate
{
    void showMenu(int index, QMouseEvent *event);
    void appendMode(IMode *mode);
    void enabledStateChanged(IMode *mode);
    void activateModeHelper(Id id);
    void extensionsInitializedHelper();

    Internal::MainWindow *m_mainWindow;
    Internal::FancyTabWidget *m_modeStack;
    Internal::FancyActionBar *m_actionBar;
    QMap<QAction*, int> m_actions;
    QVector<IMode*> m_modes;
    QVector<Command*> m_modeCommands;
    Context m_addedContexts;
    int m_oldCurrent;
    ModeManager::Style m_modeStyle = ModeManager::Style::IconsAndText;

    bool m_startingUp = true;
    Id m_pendingFirstActiveMode; // Valid before extentionsInitialized.
};

static ModeManagerPrivate *d;
static ModeManager *m_instance = nullptr;

static int indexOf(Id id)
{
    for (int i = 0; i < d->m_modes.count(); ++i) {
        if (d->m_modes.at(i)->id() == id)
            return i;
    }
    qDebug() << "Warning, no such mode:" << id.toString();
    return -1;
}

void ModeManagerPrivate::showMenu(int index, QMouseEvent *event)
{
    QTC_ASSERT(m_modes.at(index)->menu(), return);
    m_modes.at(index)->menu()->popup(event->globalPos());
}

ModeManager::ModeManager(Internal::MainWindow *mainWindow,
                         Internal::FancyTabWidget *modeStack)
{
    m_instance = this;
    d = new ModeManagerPrivate();
    d->m_mainWindow = mainWindow;
    d->m_modeStack = modeStack;
    d->m_oldCurrent = -1;
    d->m_actionBar = new Internal::FancyActionBar(modeStack);
    d->m_modeStack->addCornerWidget(d->m_actionBar);
    setModeStyle(d->m_modeStyle);

    connect(d->m_modeStack, &Internal::FancyTabWidget::currentAboutToShow,
            this, &ModeManager::currentTabAboutToChange);
    connect(d->m_modeStack, &Internal::FancyTabWidget::currentChanged,
            this, &ModeManager::currentTabChanged);
    connect(d->m_modeStack, &Internal::FancyTabWidget::menuTriggered,
            this, [](int index, QMouseEvent *e) { d->showMenu(index, e); });
}

ModeManager::~ModeManager()
{
    delete d;
    d = nullptr;
    m_instance = nullptr;
}

Id ModeManager::currentModeId()
{
    int currentIndex = d->m_modeStack->currentIndex();
    if (currentIndex < 0)
        return Id();
    return d->m_modes.at(currentIndex)->id();
}

static IMode *findMode(Id id)
{
    const int index = indexOf(id);
    if (index >= 0)
        return d->m_modes.at(index);
    return nullptr;
}

void ModeManager::activateMode(Id id)
{
    d->activateModeHelper(id);
}

void ModeManagerPrivate::activateModeHelper(Id id)
{
    if (m_startingUp) {
        m_pendingFirstActiveMode = id;
    } else {
        const int currentIndex = m_modeStack->currentIndex();
        const int newIndex = indexOf(id);
        if (newIndex != currentIndex && newIndex >= 0)
            m_modeStack->setCurrentIndex(newIndex);
    }
}

void ModeManager::extensionsInitialized()
{
    d->extensionsInitializedHelper();
}

void ModeManagerPrivate::extensionsInitializedHelper()
{
    m_startingUp = false;

    Utils::sort(m_modes, &IMode::priority);
    std::reverse(m_modes.begin(), m_modes.end());

    for (IMode *mode : m_modes)
        appendMode(mode);

    if (m_pendingFirstActiveMode.isValid())
        activateModeHelper(m_pendingFirstActiveMode);
}

void ModeManager::addMode(IMode *mode)
{
    QTC_ASSERT(d->m_startingUp, return);
    d->m_modes.append(mode);
}

void ModeManagerPrivate::appendMode(IMode *mode)
{
    const int index = m_modeCommands.count();

    m_mainWindow->addContextObject(mode);

    m_modeStack->insertTab(index, mode->widget(), mode->icon(), mode->displayName(),
                           mode->menu() != nullptr);
    m_modeStack->setTabEnabled(index, mode->isEnabled());

    // Register mode shortcut
    const Id actionId = mode->id().withPrefix("QtCreator.Mode.");
    QAction *action = new QAction(ModeManager::tr("Switch to <b>%1</b> mode").arg(mode->displayName()), m_instance);
    Command *cmd = ActionManager::registerAction(action, actionId);
    cmd->setDefaultKeySequence(QKeySequence(useMacShortcuts ? QString("Meta+%1").arg(index + 1)
                                                            : QString("Ctrl+%1").arg(index + 1)));
    m_modeCommands.append(cmd);

    m_modeStack->setTabToolTip(index, cmd->action()->toolTip());
    QObject::connect(cmd, &Command::keySequenceChanged, m_instance, [cmd, index, this] {
        m_modeStack->setTabToolTip(index, cmd->action()->toolTip());
    });

    Id id = mode->id();
    QObject::connect(action, &QAction::triggered, [this, id] {
        ModeManager::activateMode(id);
        ICore::raiseWindow(m_modeStack);
    });

    QObject::connect(mode, &IMode::enabledStateChanged, [this, mode] { enabledStateChanged(mode); });
}

void ModeManagerPrivate::enabledStateChanged(IMode *mode)
{
    int index = d->m_modes.indexOf(mode);
    QTC_ASSERT(index >= 0, return);
    d->m_modeStack->setTabEnabled(index, mode->isEnabled());

    // Make sure we leave any disabled mode to prevent possible crashes:
    if (mode->id() == ModeManager::currentModeId() && !mode->isEnabled()) {
        // This assumes that there is always at least one enabled mode.
        for (int i = 0; i < d->m_modes.count(); ++i) {
            if (d->m_modes.at(i) != mode &&
                d->m_modes.at(i)->isEnabled()) {
                ModeManager::activateMode(d->m_modes.at(i)->id());
                break;
            }
        }
    }
}

void ModeManager::removeMode(IMode *mode)
{
    const int index = d->m_modes.indexOf(mode);
    d->m_modes.remove(index);
    d->m_modeCommands.remove(index);
    d->m_modeStack->removeTab(index);

    d->m_mainWindow->removeContextObject(mode);
}

void ModeManager::addAction(QAction *action, int priority)
{
    d->m_actions.insert(action, priority);

    // Count the number of commands with a higher priority
    int index = 0;
    foreach (int p, d->m_actions) {
        if (p > priority)
            ++index;
    }

    d->m_actionBar->insertAction(index, action);
}

void ModeManager::addProjectSelector(QAction *action)
{
    d->m_actionBar->addProjectSelector(action);
    d->m_actions.insert(0, INT_MAX);
}

void ModeManager::currentTabAboutToChange(int index)
{
    if (index >= 0) {
        IMode *mode = d->m_modes.at(index);
        if (mode)
            emit currentModeAboutToChange(mode->id());
    }
}

void ModeManager::currentTabChanged(int index)
{
    // Tab index changes to -1 when there is no tab left.
    if (index < 0)
        return;

    IMode *mode = d->m_modes.at(index);
    if (!mode)
        return;

    // FIXME: This hardcoded context update is required for the Debug and Edit modes, since
    // they use the editor widget, which is already a context widget so the main window won't
    // go further up the parent tree to find the mode context.
    ICore::updateAdditionalContexts(d->m_addedContexts, mode->context());
    d->m_addedContexts = mode->context();

    IMode *oldMode = nullptr;
    if (d->m_oldCurrent >= 0)
        oldMode = d->m_modes.at(d->m_oldCurrent);
    d->m_oldCurrent = index;
    emit currentModeChanged(mode->id(), oldMode ? oldMode->id() : Id());
}

void ModeManager::setFocusToCurrentMode()
{
    IMode *mode = findMode(currentModeId());
    QTC_ASSERT(mode, return);
    QWidget *widget = mode->widget();
    if (widget) {
        QWidget *focusWidget = widget->focusWidget();
        if (!focusWidget)
            focusWidget = widget;
        focusWidget->setFocus();
    }
}

void ModeManager::setModeStyle(ModeManager::Style style)
{
    const bool visible = style != Style::Hidden;
    const bool iconsOnly = style == Style::IconsOnly;

    d->m_modeStyle = style;
    d->m_actionBar->setIconsOnly(iconsOnly);
    d->m_modeStack->setIconsOnly(iconsOnly);
    d->m_modeStack->setSelectionWidgetVisible(visible);
}

void ModeManager::cycleModeStyle()
{
    auto nextStyle = Style((int(modeStyle()) + 1) % 3);
    setModeStyle(nextStyle);
}

ModeManager::Style ModeManager::modeStyle()
{
    return d->m_modeStyle;
}

ModeManager *ModeManager::instance()
{
    return m_instance;
}

IMode *ModeManager::currentMode()
{
    const int currentIndex = d->m_modeStack->currentIndex();
    return currentIndex < 0 ? nullptr : d->m_modes.at(currentIndex);
}

} // namespace Core