Code refactor

More flexible tool API
Minor code format fixes
Clipboard freeze fixed(?)
Arrow correcly growing close to the start point
Improve maintainability
Add undo/redo stack

src/tools/abstractactiontool.cpp

@@ -0,0 +1,71 @@
+// 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 "abstractactiontool.h"
+
+AbstractActionTool::AbstractActionTool(QObject *parent) : CaptureTool(parent) {
+
+}
+
+bool AbstractActionTool::isValid() const {
+    return true;
+}
+
+bool AbstractActionTool::isSelectable() const {
+    return false;
+}
+
+bool AbstractActionTool::showMousePreview() const {
+    return false;
+}
+
+QWidget *AbstractActionTool::widget() {
+    return nullptr;
+}
+
+QWidget *AbstractActionTool::configurationWidget() {
+    return nullptr;
+}
+
+void AbstractActionTool::undo(QPixmap &pixmap) {
+    Q_UNUSED(pixmap);
+}
+
+void AbstractActionTool::process(QPainter &painter, const QPixmap &pixmap, bool recordUndo) {
+    Q_UNUSED(painter);
+    Q_UNUSED(pixmap);
+    Q_UNUSED(recordUndo);
+}
+
+void AbstractActionTool::paintMousePreview(
+        QPainter &painter, const CaptureContext &context)
+{
+    Q_UNUSED(painter);
+    Q_UNUSED(context);
+}
+
+void AbstractActionTool::drawEnd(const QPoint &p) {
+    Q_UNUSED(p);
+}
+
+void AbstractActionTool::drawMove(const QPoint &p) {
+    Q_UNUSED(p);
+}
+
+void AbstractActionTool::drawStart(const CaptureContext &context) {
+    Q_UNUSED(context);
+}