[WIP] Add line thickness to side panel (#374)

* Add thickness slider

* Fix enums compatibility

* Rename ColorPickerWidget to SidePanelWidget

src/widgets/panel/sidepanelwidget.cpp

@@ -0,0 +1,188 @@
+// Copyright(c) 2017-2018 Alejandro Sirgo Rica & Contributors
+//
+// This file is part of Flameshot.
+//
+//     Flameshot 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 3 of the License, or
+//     (at your option) any later version.
+//
+//     Flameshot 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 Flameshot.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "sidepanelwidget.h"
+#include "src/utils/pathinfo.h"
+#include "src/utils/colorutils.h"
+#include <QVBoxLayout>
+#include <QFormLayout>
+#include <QPushButton>
+#include <QLabel>
+#include <QKeyEvent>
+#include <QSlider>
+
+class QColorPickingEventFilter : public QObject {
+public:
+
+    explicit QColorPickingEventFilter(
+            SidePanelWidget *pw, QObject *parent = nullptr) :
+        QObject(parent), m_pw(pw) {}
+
+    bool eventFilter(QObject *, QEvent *event) override {
+        event->accept();
+        switch (event->type()) {
+        case QEvent::MouseMove:
+            return m_pw->handleMouseMove(static_cast<QMouseEvent *>(event));
+        case QEvent::MouseButtonPress:
+            return m_pw->handleMouseButtonPressed(
+                        static_cast<QMouseEvent *>(event));
+        case QEvent::KeyPress:
+            return m_pw->handleKeyPress(static_cast<QKeyEvent *>(event));
+        default:
+            break;
+        }
+        return false;
+    }
+
+private:
+    SidePanelWidget *m_pw;
+};
+
+////////////////////////
+
+SidePanelWidget::SidePanelWidget(QPixmap *p, QWidget *parent) :
+    QWidget(parent), m_pixmap(p), m_eventFilter(nullptr)
+{
+    m_layout = new QVBoxLayout(this);
+
+    QFormLayout *colorForm = new QFormLayout();
+    m_thicknessSlider = new QSlider(Qt::Horizontal);
+    m_thicknessSlider->setValue(m_thickness);
+    m_colorLabel = new QLabel();
+    m_colorLabel->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
+    colorForm->addRow(tr("Active thickness:"), m_thicknessSlider);
+    colorForm->addRow(tr("Active color:"), m_colorLabel);
+    m_layout->addLayout(colorForm);
+
+    connect(m_thicknessSlider, &QSlider::sliderReleased,
+            this, &SidePanelWidget::updateCurrentThickness);
+    connect(this, &SidePanelWidget::thicknessChanged,
+            this, &SidePanelWidget::updateThickness);
+
+    QColor background = this->palette().background().color();
+    bool isDark = ColorUtils::colorIsDark(background);
+    QString modifier = isDark ? PathInfo::whiteIconPath() :
+                                PathInfo::blackIconPath();
+    QIcon grabIcon(modifier + "colorize.svg");
+    m_colorGrabButton = new QPushButton(grabIcon, "");
+    updateGrabButton(false);
+    connect(m_colorGrabButton, &QPushButton::pressed,
+            this, &SidePanelWidget::colorGrabberActivated);
+    m_layout->addWidget(m_colorGrabButton);
+
+    m_colorWheel = new color_widgets::ColorWheel(this);
+    m_colorWheel->setColor(m_color);
+    connect(m_colorWheel, &color_widgets::ColorWheel::mouseReleaseOnColor, this,
+            &SidePanelWidget::colorChanged);
+    connect(m_colorWheel, &color_widgets::ColorWheel::colorChanged, this,
+            &SidePanelWidget::updateColorNoWheel);
+    m_layout->addWidget(m_colorWheel);
+}
+
+void SidePanelWidget::updateColor(const QColor &c) {
+    m_color = c;
+    m_colorLabel->setStyleSheet(
+                QString("QLabel { background-color : %1; }").arg(c.name()));
+    m_colorWheel->setColor(m_color);
+}
+
+void SidePanelWidget::updateThickness(const int &t)
+{
+    m_thickness = qBound(0, t, 100);
+    m_thicknessSlider->setValue(m_thickness);
+}
+
+void SidePanelWidget::updateColorNoWheel(const QColor &c) {
+    m_color = c;
+    m_colorLabel->setStyleSheet(
+                QString("QLabel { background-color : %1; }").arg(c.name()));
+}
+
+void SidePanelWidget::updateCurrentThickness()
+{
+    emit thicknessChanged(m_thicknessSlider->value());
+}
+
+void SidePanelWidget::colorGrabberActivated() {
+    grabKeyboard();
+    grabMouse(Qt::CrossCursor);
+    setMouseTracking(true);
+    m_colorBackup = m_color;
+    if (!m_eventFilter) {
+        m_eventFilter = new QColorPickingEventFilter(this, this);
+    }
+    installEventFilter(m_eventFilter);
+    updateGrabButton(true);
+}
+
+void SidePanelWidget::releaseColorGrab() {
+    setMouseTracking(false);
+    removeEventFilter(m_eventFilter);
+    releaseMouse();
+    releaseKeyboard();
+    setFocus();
+    updateGrabButton(false);
+}
+
+QColor SidePanelWidget::grabPixmapColor(const QPoint &p) {
+    QColor c;
+    if (m_pixmap) {
+        QPixmap pixel = m_pixmap->copy(QRect(p, p));
+        c = pixel.toImage().pixel(0,0);
+    }
+    return c;
+}
+
+bool SidePanelWidget::handleKeyPress(QKeyEvent *e) {
+    if (e->key() == Qt::Key_Space) {
+        emit togglePanel();
+    } else if (e->key() == Qt::Key_Escape) {
+        releaseColorGrab();
+        updateColor(m_colorBackup);
+    } else if (e->key() == Qt::Key_Return || e->key() == Qt::Key_Enter) {
+        updateColor(grabPixmapColor(QCursor::pos()));
+        releaseColorGrab();
+        emit colorChanged(m_color);
+    }
+    return true;
+}
+
+bool SidePanelWidget::handleMouseButtonPressed(QMouseEvent *e) {
+    if (m_colorGrabButton->geometry().contains(e->pos()) ||
+            e->button() == Qt::RightButton)
+    {
+        updateColorNoWheel(m_colorBackup);
+    } else if (e->button() == Qt::LeftButton) {
+        updateColor(grabPixmapColor(QCursor::pos()));
+    }
+    releaseColorGrab();
+    emit colorChanged(m_color);
+    return true;
+}
+
+bool SidePanelWidget::handleMouseMove(QMouseEvent *e) {
+    updateColorNoWheel(grabPixmapColor(e->globalPos()));
+    return true;
+}
+
+void SidePanelWidget::updateGrabButton(const bool activated) {
+    if (activated) {
+        m_colorGrabButton->setText(tr("Press ESC to cancel"));
+    } else {
+        m_colorGrabButton->setText(tr("Grab Color"));
+    }
+}