Hands-On High Performance Programming with Qt 5

Solution

The obvious solution, that is, replacing all of the images with fast-loading bitmaps, was out of the question due to a lack of time and also because of the sunken costs fallacy. Thus, the better algorithm/data structure strategy was not possible. The next strategy that offered itself up was caching the already rendered SVG icons. Due to this, we employed the caching technique and avoided needless repetition of work, that is, opening and parsing the SVG icon files:

1. First, we created a cache for the SVG icons using the QSvgRenderer class for reading and parsing the XML files:

QMap<QString, QSvgRenderer*> svgMap_; auto iter = svgMap_.constFind(path);if (iter == svgMap_.constEnd()){ iter = svgMap_.insert(path, new QSvgRenderer(path)); ...