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https://github.com/qelectrotech/qelectrotech-source-mirror.git
synced 2026-10-03 17:34:12 +02:00
Jeff Patterson
3e34a6d55f
QGraphicsView::render() paints only what the scene draws, so a scene without a background brush left the off-screen buffer uninitialized and the inversion turned that memory into noise. The buffer is now filled white first, which the inversion turns into the Base color. listenToScene() connected a new receiver on every setScene() call and never dropped the previous scene's. It now keeps a single connection and replaces it. Test in tst_qetpalette: paletteViewFillsWhatTheSceneLeavesBlank.
74 lines
2.7 KiB
C++
74 lines
2.7 KiB
C++
/*
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Copyright 2006-2026 The QElectroTech Team
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This file is part of QElectroTech.
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QElectroTech is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 2 of the License, or
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(at your option) any later version.
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QElectroTech is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with QElectroTech. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef PALETTE_GRAPHICS_VIEW_H
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#define PALETTE_GRAPHICS_VIEW_H
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#include <QGraphicsView>
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class QPainter;
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/**
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A QGraphicsView that shows its scene with inverted lightness while its
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palette is dark: white becomes the palette's Base color, black its Text
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color, and colored strokes keep their hue. The scene itself is left as
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drawn, so printing and exporting it still give black on white. On a
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light palette the view paints exactly as QGraphicsView does.
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The view paints through QGraphicsView::render() into an image and blits
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the inverted image. QGraphicsView delivers scene updates straight to
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its viewport when nobody listens to QGraphicsScene::changed(), and in
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that mode the scene clears its "update everything" flag only when the
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items are painted straight onto the viewport, which never happens
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here: from the second QGraphicsScene::update() on, every scene update
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and every item update would wait for an unrelated repaint. So the view
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listens to changed() on every scene it is given, which makes the scene
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clear the flag before it emits. Set the scene through this class, not
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through a QGraphicsView pointer.
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*/
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class PaletteGraphicsView : public QGraphicsView
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{
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Q_OBJECT
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public:
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explicit PaletteGraphicsView(QWidget *parent = nullptr);
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explicit PaletteGraphicsView(QGraphicsScene *scene, QWidget *parent = nullptr);
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void setScene(QGraphicsScene *scene);
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bool invertsLightness() const;
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protected:
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bool eventFilter(QObject *watched, QEvent *event) override;
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void paintEvent(QPaintEvent *event) override;
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/**
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Called with true right before the scene is rendered for an
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inverted display and with false right after, so a scene can
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adapt what it draws (a softer grid, for instance). Does
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nothing by default.
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*/
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virtual void paintingInverted(bool inverted);
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private:
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void listenToScene(QGraphicsScene *scene);
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void paintInverted(const QRect &area);
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void drawRubberBand(QPainter &painter);
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QMetaObject::Connection m_scene_connection;
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};
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#endif
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