viewwidget.cpp

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/*
 * This file is part of the PulseView project.
 *
 * Copyright (C) 2014 Joel Holdsworth <joel@airwebreathe.org.uk>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 */

#include <QApplication>
#include <QMouseEvent>
#include <QTouchEvent>

#include "tracetreeitem.hpp"
#include "view.hpp"
#include "viewwidget.hpp"

using std::any_of;
using std::shared_ptr;
using std::vector;

namespace pv {
namespace view {

ViewWidget::ViewWidget(View &parent) :
    QWidget(&parent),
    view_(parent),
    item_dragging_(false)
{
    setFocusPolicy(Qt::ClickFocus);
    setAttribute(Qt::WA_AcceptTouchEvents, true);
    setMouseTracking(true);
}

void ViewWidget::clear_selection()
{
    const auto items = this->items();
    for (auto &i : items)
        i->select(false);
}

void ViewWidget::item_hover(const shared_ptr<ViewItem> &item)
{
    (void)item;
}

void ViewWidget::item_clicked(const shared_ptr<ViewItem> &item)
{
    (void)item;
}

bool ViewWidget::accept_drag() const
{
    const vector< shared_ptr<TimeItem> > items(view_.time_items());
    const vector< shared_ptr<TraceTreeItem> > trace_tree_items(
        view_.list_by_type<TraceTreeItem>());

    const bool any_row_items_selected = any_of(
        trace_tree_items.begin(), trace_tree_items.end(),
        [](const shared_ptr<TraceTreeItem> &r) { return r->selected(); });

    const bool any_time_items_selected = any_of(items.begin(), items.end(),
        [](const shared_ptr<TimeItem> &i) { return i->selected(); });

    if (any_row_items_selected && !any_time_items_selected) {
        // Check all the drag items share a common owner
        TraceTreeItemOwner *item_owner = nullptr;
        for (shared_ptr<TraceTreeItem> r : trace_tree_items)
            if (r->dragging()) {
                if (!item_owner)
                    item_owner = r->owner();
                else if (item_owner != r->owner())
                    return false;
            }

        return true;
    } else if (any_time_items_selected && !any_row_items_selected) {
        return true;
    }

    // A background drag is beginning
    return true;
}

bool ViewWidget::mouse_down() const
{
    return mouse_down_point_.x() != INT_MIN &&
        mouse_down_point_.y() != INT_MIN;
}

void ViewWidget::drag_items(const QPoint &delta)
{
    bool item_dragged = false;

    // Drag the row items
    const vector< shared_ptr<RowItem> > row_items(
        view_.list_by_type<RowItem>());
    for (shared_ptr<RowItem> r : row_items)
        if (r->dragging()) {
            r->drag_by(delta);

            // Ensure the trace is selected
            r->select();

            item_dragged = true;
        }

    // If an item is being dragged, update the stacking
    TraceTreeItemOwner *item_owner = nullptr;
    const vector< shared_ptr<TraceTreeItem> > trace_tree_items(
        view_.list_by_type<TraceTreeItem>());
    for (shared_ptr<TraceTreeItem> i : trace_tree_items)
        if (i->dragging())
            item_owner = i->owner();

    if (item_owner) {
        item_owner->restack_items();
        for (shared_ptr<TraceTreeItem> i : trace_tree_items)
            i->animate_to_layout_v_offset();
    }

    // Drag the time items
    const vector< shared_ptr<TimeItem> > items(view_.time_items());
    for (auto &i : items)
        if (i->dragging()) {
            i->drag_by(delta);
            item_dragged = true;
        }

    // Do the background drag
    if (!item_dragged)
        drag_by(delta);
}

void ViewWidget::drag()
{
}

void ViewWidget::drag_by(const QPoint &delta)
{
    (void)delta;
}

void ViewWidget::drag_release()
{
}

void ViewWidget::mouse_left_press_event(QMouseEvent *event)
{
    (void)event;

    const bool ctrl_pressed =
        QApplication::keyboardModifiers() & Qt::ControlModifier;

    // Clear selection if control is not pressed and this item is unselected
    if ((!mouse_down_item_ || !mouse_down_item_->selected()) &&
        !ctrl_pressed)
        clear_selection();

    // Set the signal selection state if the item has been clicked
    if (mouse_down_item_) {
        if (ctrl_pressed)
            mouse_down_item_->select(!mouse_down_item_->selected());
        else
            mouse_down_item_->select(true);
    }

    // Save the offsets of any signals which will be dragged
    bool item_dragged = false;
    const auto items = this->items();
    for (auto &i : items)
        if (i->selected()) {
            item_dragged = true;
            i->drag();
        }

    // Do the background drag
    if (!item_dragged)
        drag();

    selection_changed();
}

void ViewWidget::mouse_left_release_event(QMouseEvent *event)
{
    assert(event);

    auto items = this->items();
    const bool ctrl_pressed =
        QApplication::keyboardModifiers() & Qt::ControlModifier;

    // Unselect everything if control is not pressed
    const shared_ptr<ViewItem> mouse_over =
        get_mouse_over_item(event->pos());

    for (auto &i : items)
        i->drag_release();

    if (item_dragging_)
        view_.restack_all_trace_tree_items();
    else {
        if (!ctrl_pressed) {
            for (shared_ptr<ViewItem> i : items)
                if (mouse_down_item_ != i)
                    i->select(false);

            if (mouse_down_item_)
                item_clicked(mouse_down_item_);
        }
    }

    item_dragging_ = false;
}

bool ViewWidget::touch_event(QTouchEvent *e)
{
    (void)e;
    return false;
}

bool ViewWidget::event(QEvent *event)
{
    switch (event->type()) {
    case QEvent::TouchBegin:
    case QEvent::TouchUpdate:
    case QEvent::TouchEnd:
        if (touch_event(static_cast<QTouchEvent *>(event)))
            return true;
        break;

    default:
        break;
    }

    return QWidget::event(event);
}

void ViewWidget::mousePressEvent(QMouseEvent *event)
{
    assert(event);

    mouse_down_point_ = event->pos();
    mouse_down_item_ = get_mouse_over_item(event->pos());

    if (event->button() & Qt::LeftButton)
        mouse_left_press_event(event);
}

void ViewWidget::mouseReleaseEvent(QMouseEvent *event)
{
    assert(event);
    if (event->button() & Qt::LeftButton)
        mouse_left_release_event(event);

    mouse_down_point_ = QPoint(INT_MIN, INT_MIN);
    mouse_down_item_ = nullptr;
}

void ViewWidget::mouseMoveEvent(QMouseEvent *e)
{
    assert(e);
    mouse_point_ = e->pos();

    if (!e->buttons())
        item_hover(get_mouse_over_item(e->pos()));
    else if (e->buttons() & Qt::LeftButton) {
        if (!item_dragging_) {
            if ((e->pos() - mouse_down_point_).manhattanLength() <
                QApplication::startDragDistance())
                return;

            if (!accept_drag())
                return;

            item_dragging_ = true;
        }

        // Do the drag
        drag_items(e->pos() - mouse_down_point_);
    }
}

void ViewWidget::leaveEvent(QEvent*)
{
    mouse_point_ = QPoint(-1, -1);
    update();
}

} // namespace view
} // namespace pv