Implement highlighter tool

Fixes #56

src/cropeditor/cropscene.cpp

@@ -16,6 +16,7 @@
 #include <cropeditor/drawing/bluritem.hpp>
 #include <cropeditor/drawing/ellipseitem.hpp>
 #include <cropeditor/drawing/eraseritem.hpp>
+#include <cropeditor/drawing/highlighter.hpp>
 #include <cropeditor/drawing/lineitem.hpp>
 #include <cropeditor/drawing/pathitem.hpp>
 #include <cropeditor/drawing/rectitem.hpp>
@@ -41,6 +42,7 @@ CropScene::CropScene(QObject *parent, QPixmap pixmap)
     addDrawingAction(menu, tr("Straight line"), ":/icons/line.png", [] { return new LineItem; });
     addDrawingAction(menu, tr("Text"), ":/icons/text.png", [] { return new TextItem; });
     addDrawingAction(menu, tr("Rectangle"), ":/icons/rectangle.png", [] { return new RectItem; });
+    addDrawingAction(menu, tr("Highlighter"), ":/icons/highlighter.png", [] { return new Highlighter; });
     addDrawingAction(menu, tr("Ellipse"), ":/icons/circle.png", [] { return new EllipseItem; });
     addDrawingAction(menu, tr("Arrow"), ":/icons/arrow.png", [] { return new ArrowItem; });
 

src/cropeditor/drawing/highlighter.cpp

@@ -0,0 +1,37 @@
+#include "highlighter.hpp"
+
+#include <QImage>
+
+void Highlighter::mouseDragEvent(QGraphicsSceneMouseEvent *, CropScene *scene) {
+    if (pos.isNull()) {
+        pos = scene->cursorPos();
+        rect = scene->addRect(QRect(scene->cursorPos().toPoint(), QSize(1, 1)), QPen(scene->highlight()), Qt::NoBrush);
+        pixmap = scene->addPixmap(scene->pixmap().copy(rect->rect().toRect()));
+        pixmap->setPos(scene->cursorPos());
+    } else {
+        QPointF p = scene->cursorPos();
+        rect->setRect(QRect(qMin(pos.x(), p.x()), qMin(pos.y(), p.y()), qAbs(pos.x() - p.x()), qAbs(pos.y() - p.y())));
+        auto area = rect->rect();
+        if (area.width() > 1 && area.height() > 1 && area.top() > 1 && area.left() > 1) {
+            // toImage conversion needed for access to the underlying image data for altering
+            auto pm = scene->pixmap().copy(rect->rect().toRect()).toImage();
+            if (pm.format() != QImage::Format_RGB32) {
+                pm = pm.convertToFormat(QImage::Format_RGB32);
+            }
+            for (int y = 0; y < pm.height(); y++) {
+                QRgb *line = (QRgb *)pm.scanLine(y);
+                for (int x = 0; x < pm.width(); x++) {
+                    QRgb &pix = line[x];
+                    pix = qRgb(qMin(255, qRed(pix)), qMin(255, qGreen(pix)), 0);
+                }
+            }
+            pixmap->setPixmap(QPixmap::fromImage(pm));
+        }
+        pixmap->setPos(rect->rect().topLeft());
+    }
+}
+
+void Highlighter::mouseDragEndEvent(QGraphicsSceneMouseEvent *, CropScene *) {
+    delete rect;
+    rect = 0;
+}

src/cropeditor/drawing/highlighter.hpp

@@ -0,0 +1,21 @@
+#ifndef HIGHLIGHTER_HPP
+#define HIGHLIGHTER_HPP
+
+#include "drawitem.hpp"
+#include <QPointF>
+
+class Highlighter : public DrawItem {
+public:
+    QString name() override {
+        return "Highlighter";
+    }
+    void mouseDragEvent(QGraphicsSceneMouseEvent *, CropScene *scene) override;
+    void mouseDragEndEvent(QGraphicsSceneMouseEvent *, CropScene *) override;
+
+private:
+    QPointF pos;
+    QGraphicsRectItem *rect = 0;
+    QGraphicsPixmapItem *pixmap;
+};
+
+#endif /* HIGHLIGHTER_HPP */

src/icon.qrc

@@ -17,5 +17,6 @@
         <file>icons/cancel.png</file>
         <file>icons/crop.png</file>
         <file>icons/circle.png</file>
+        <file>icons/highlighter.png</file>
     </qresource>
 </RCC>

src/icons/highlighter.svg

@@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   viewBox="0 0 24 24"
+   version="1.1"
+   id="svg92"
+   sodipodi:docname="highlighter.svg"
+   inkscape:version="0.92.2 (5c3e80d, 2017-08-06)"
+   width="24"
+   height="24"
+   inkscape:export-filename="/home/arsen/Projects/KShare/src/icons/highlighter.png"
+   inkscape:export-xdpi="96"
+   inkscape:export-ydpi="96">
+  <metadata
+     id="metadata98">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <defs
+     id="defs96" />
+  <sodipodi:namedview
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1"
+     objecttolerance="10"
+     gridtolerance="10"
+     guidetolerance="10"
+     inkscape:pageopacity="0"
+     inkscape:pageshadow="2"
+     inkscape:window-width="785"
+     inkscape:window-height="855"
+     id="namedview94"
+     showgrid="false"
+     inkscape:zoom="16"
+     inkscape:cx="9.6803279"
+     inkscape:cy="12.750987"
+     inkscape:window-x="805"
+     inkscape:window-y="35"
+     inkscape:window-maximized="0"
+     inkscape:current-layer="svg92" />
+  <path
+     style="fill:#000000;stroke-width:1.84643126"
+     d="M 16.610669,0 C 11.083055,5.5425551 5.5348512,11.064519 0,16.599837 0,19.066559 0,21.533279 0,24 2.4667167,24 4.9334335,24 7.4001502,24 12.937932,18.467607 18.467824,12.927324 24,7.3893312 21.536286,4.9268223 19.077388,2.4594998 16.610669,0 Z M 15.53238,3.6856499 c 1.592788,1.5939894 3.185579,3.187979 4.778363,4.7819684 C 18.717959,6.8736289 17.125168,5.2796393 15.53238,3.6856499 Z m 0,0 c 1.592788,1.5939894 3.185579,3.187979 4.778363,4.7819684 C 15.95333,12.84467 11.588321,17.214185 7.2090156,21.569343 5.615026,19.975355 4.0210366,18.381364 2.4270471,16.787375 6.7954916,12.420133 11.163938,8.0528919 15.53238,3.6856499 Z"
+     id="path90"
+     inkscape:connector-curvature="0" />
+</svg>

src/src.pro

@@ -61,6 +61,7 @@ SOURCES += main.cpp\
     cropeditor/drawing/eraseritem.cpp \
     cropeditor/drawing/rectitem.cpp \
     cropeditor/drawing/ellipseitem.cpp \
+    cropeditor/drawing/highlighter.cpp \
     hotkeyinputdialog.cpp \
     cropeditor/drawing/arrowitem.cpp \
     uploaders/default/imgursettingsdialog.cpp \
@@ -113,6 +114,7 @@ HEADERS  += mainwindow.hpp \
     cropeditor/drawing/eraseritem.hpp \
     cropeditor/drawing/rectitem.hpp \
     cropeditor/drawing/ellipseitem.hpp \
+    cropeditor/drawing/highlighter.hpp \
     hotkeyinputdialog.hpp \
     cropeditor/drawing/arrowitem.hpp \
     uploaders/default/imgursettingsdialog.hpp \