Dear all,
I've recently experienced that NetBeans is unresponsive for 5-10 secs
after the main screen opens. It does not really bother me as I open
NetBeans up once or twice a week. I have ~46 projects loaded (mostly
NetBeans modules).
I've tried to profile what is happening. Though right now the profiler
attachment crashes (an other issue maybe it is just on my machine) the
JVM running the profiled NetBeans in 10-15 secs, I could get some
valuable info.
It seems there is a performance bottleneck in multitabs implementation.
org.netbeans.core.multitabs.impl.TabDataRenderer.getPreferredWidth(Object)
is being called several times spending considerable amount of time
setting the text on a JLabel over and over:
https://github.com/apache/netbeans/blob/06b3e677d9ea4dbd9987c8245fe5be776e8245f8/platform/core.multitabs/src/org/netbeans/core/multitabs/impl/TabDataRenderer.java#L144
The purpose of these calls is to properly measure the width of the
rendered component.
I've tried to cheat by replacing:
renderer.label.setText( text );
renderer.label.setIcon( icon );
res = renderer.getPreferredSize().width;
With:
AffineTransform transform = new AffineTransform();
FontRenderContext frc = new FontRenderContext(transform, true, true);
Font font = renderer.label.getFont();
res = icon.getIconWidth() + renderer.label.getIconTextGap() + (int)
font.getStringBounds(text, frc).getWidth();
That, kind of, worked. The IDE starts up faster there is no visible
side-effect (yet), however I would like someone who is more into swing
to come up with a proper implementation, that handles HIDPI and html
labels. Should not be hard, I just do not have the proper knowledge.
