Bug 82743 [Markers] improved problem filter needed (OR clauses)
when working with large workspaces I find the current problems filter not powerful enough. If I were able to AND and OR the conditions available from the UI then I would solve all my use cases. my most needed one is : I would like to see ERRORS anywhere in the workspace OR WARNINGS in the current selected project
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/MarkerList.java
* Returns the number of warning markers in the list 
     * 
     * @return the number of warning markers
     */
    public int getWarnings() {
        return getMarkerCounts()[IMarker.SEVERITY_WARNING];
    }
    /**
     * Returns an array of marker counts where getMarkerCounts()[severity] is the number
     * of markers in the list with the given severity. 
     * 
     * @return an array of marker counts
     */
    private int[] getMarkerCounts() {
        if (markerCounts == null) {
            markerCounts = new int[] { 0, 0, 0 };
            for (int idx = 0; idx < markers.length; idx++) {
                ConcreteMarker marker = markers[idx];
                if (marker instanceof ProblemMarker) {
                    int severity = ((ProblemMarker) markers[idx]).getSeverity();
                    if (severity >= 0 && severity <= 2) {
                        markerCounts[severity]++;
                    }
                }
            }
        }
        return markerCounts;
    }
}