org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramUtils.java

   1 /*******************************************************************************
   2  * Copyright (c) 2009, 2011, 2012 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *   William Bourque - Initial API and implementation
  11  *   Francois Chouinard - Cleanup and refactoring
  12  *   Francois Chouinard - Moved from LTTng to TMF
  13  *******************************************************************************/
  14
  15 package org.eclipse.linuxtools.tmf.ui.views.histogram;
  16
  17 import org.eclipse.swt.graphics.GC;
  18 import org.eclipse.swt.widgets.Composite;
  19
  20 /**
  21  * <b><u>HistogramUtils</u></b>
  22  * <p>
  23  * Bunch of conversion utilities.
  24  * <p>
  25  */
  26 public abstract class HistogramUtils {
  27
  28     // ------------------------------------------------------------------------
  29     // Operations
  30     // ------------------------------------------------------------------------
  31
  32     /**
  33      * Format a long representing nanoseconds into a string of the form
  34      * "[seconds].[nanoseconds]" with the appropriate zero-padding.
  35      * <p>
  36      *
  37      * @param ns the timestamp in nanoseconds
  38      * @return the formatted string
  39      */
  40     public static String nanosecondsToString(long ns) {
  41         ns = Math.abs(ns);
  42         String time = Long.toString(ns);
  43
  44         int length = time.length();
  45         if (time.length() > 9) {
  46             // Just insert the decimal dot
  47             time = time.substring(0, length - 9) + "." + time.substring(length - 9); //$NON-NLS-1$
  48             return time;
  49         }
  50
  51         // Zero-pad the value
  52         for (int i = length; i < 9; i++) {
  53             time = "0" + time; //$NON-NLS-1$
  54         }
  55         time = "0." + time; //$NON-NLS-1$
  56         return time;
  57     }
  58
  59     /**
  60      * Convert a string representing a time to the corresponding long.
  61      * <p>
  62      *
  63      * @param time the string to convert
  64      * @return the corresponding nanoseconds value
  65      */
  66     public static long stringToNanoseconds(String time) {
  67
  68         long result = 0L;
  69         StringBuffer buffer = new StringBuffer(time);
  70
  71         try {
  72             int dot = buffer.indexOf("."); //$NON-NLS-1$
  73
  74             // Prepend a "." if none was found (assume ns)
  75             if (dot == -1) {
  76                 buffer.insert(0, "."); //$NON-NLS-1$
  77                 dot = 0;
  78             }
  79
  80             // Zero-pad the string for nanoseconds
  81             for (int i = buffer.length() - dot - 1; i < 9; i++)
  82                 buffer.append("0"); //$NON-NLS-1$
  83
  84             // Remove the extra decimals if present
  85             int nbDecimals = buffer.substring(dot + 1).length();
  86             if (nbDecimals > 9)
  87                 buffer.delete(buffer.substring(0, dot + 1 + 9).length(), buffer.length());
  88
  89             // Do the conversion
  90             long seconds = (dot > 0) ? Long.parseLong(buffer.substring(0, dot)) : 0;
  91             seconds = Math.abs(seconds);
  92             long nanosecs = Long.parseLong(buffer.substring(dot + 1));
  93             result = seconds * 1000000000 + nanosecs;
  94
  95         } catch (NumberFormatException e) {
  96             // TODO: Find something interesting to say
  97         }
  98
  99         return result;
 100     }
 101
 102     /**
 103      * Calculate the width of a String.
 104      * <p>
 105      *
 106      * @param parent The control used as reference
 107      * @param text The Text to measure
 108      *
 109      * @return The result size
 110      */
 111     public static int getTextSizeInControl(Composite parent, String text) {
 112
 113         GC controlGC = new GC(parent);
 114
 115         int textSize = 0;
 116         for (int pos = 0; pos < text.length(); pos++) {
 117             textSize += controlGC.getAdvanceWidth(text.charAt(pos));
 118         }
 119         // Add an extra space
 120         textSize += controlGC.getAdvanceWidth(' ');
 121
 122         controlGC.dispose();
 123
 124         return textSize;
 125     }
 126
 127 }