Mercurial > hg > svgui
view layer/ScrollableImageCache.h @ 1043:fccee028a522 3.0-integration
Merge from branch "spectrogram-minor-refactor"
author | Chris Cannam |
---|---|
date | Thu, 04 Feb 2016 11:18:08 +0000 |
parents | 55ac6ac1982e |
children | 5144d7185fb5 |
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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ /* Sonic Visualiser An audio file viewer and annotation editor. Centre for Digital Music, Queen Mary, University of London. 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. See the file COPYING included with this distribution for more information. */ #ifndef SCROLLABLE_IMAGE_CACHE_H #define SCROLLABLE_IMAGE_CACHE_H #include "base/BaseTypes.h" #include "view/LayerGeometryProvider.h" #include <QImage> #include <QRect> #include <QPainter> /** * A cached image for a view that scrolls horizontally, primarily the * spectrogram. The cache object holds an image, reports the size of * the image (likely the same as the underlying view, but it's the * caller's responsibility to set the size appropriately), can scroll * the image, and can report and update which contiguous horizontal * range of the image is valid. * * The only way to *update* the valid area in a cache is to draw to it * using the drawImage call. */ class ScrollableImageCache { public: ScrollableImageCache(const LayerGeometryProvider *v = 0) : m_v(v), m_left(0), m_width(0), m_startFrame(0), m_zoomLevel(0) {} void invalidate() { m_width = 0; } bool isValid() const { return m_width > 0; } QSize getSize() const { return m_image.size(); } void resize(QSize newSize) { m_image = QImage(newSize, QImage::Format_ARGB32_Premultiplied); invalidate(); } int getValidLeft() const { return m_left; } int getValidWidth() const { return m_width; } int getValidRight() const { return m_left + m_width; } QRect getValidArea() const { return QRect(m_left, 0, m_width, m_image.height()); } int getZoomLevel() const { return m_zoomLevel; } void setZoomLevel(int zoom) { m_zoomLevel = zoom; invalidate(); } sv_frame_t getStartFrame() const { return m_startFrame; } /** * Set the start frame and invalidate the cache. To scroll, * i.e. to set the start frame while retaining cache validity * where possible, use scrollTo() instead. */ void setStartFrame(sv_frame_t frame) { m_startFrame = frame; invalidate(); } const QImage &getImage() const { return m_image; } /** * Set the new start frame for the cache, if possible also moving * along any existing valid data within the cache so that it * continues to be valid for the new start frame. */ void scrollTo(sv_frame_t newStartFrame); /** * Take a left coordinate and width describing a region, and * adjust them so that they are contiguous with the cache valid * region and so that the union of the adjusted region with the * cache valid region contains the supplied region. */ void adjustToTouchValidArea(int &left, int &width, bool &isLeftOfValidArea) const; /** * Draw from an image onto the cache. The supplied image must have * the same height as the cache and the full height is always * drawn. The left and width parameters determine the target * region of the cache, the imageLeft and imageWidth parameters * the source region of the image. */ void drawImage(int left, int width, QImage image, int imageLeft, int imageWidth); private: const LayerGeometryProvider *m_v; QImage m_image; int m_left; // of valid region int m_width; // of valid region sv_frame_t m_startFrame; int m_zoomLevel; }; #endif