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qgsscalecombobox.cpp
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1 /***************************************************************************
2  qgsscalecombobox.h
3  ------------------------
4  begin : January 7, 2012
5  copyright : (C) 2012 by Alexander Bruy
6  email : alexander dot bruy at gmail dot com
7  ***************************************************************************/
8 
9 /***************************************************************************
10  * *
11  * This program is free software; you can redistribute it and/or modify *
12  * it under the terms of the GNU General Public License as published by *
13  * the Free Software Foundation; either version 2 of the License, or *
14  * (at your option) any later version. *
15  * *
16  ***************************************************************************/
17 
18 #include "qgis.h"
19 #include "qgslogger.h"
20 #include "qgsscalecombobox.h"
21 
22 #include <QAbstractItemView>
23 #include <QLocale>
24 #include <QSettings>
25 #include <QLineEdit>
26 
27 QgsScaleComboBox::QgsScaleComboBox( QWidget* parent ) : QComboBox( parent ), mScale( 1.0 )
28 {
29  updateScales();
30 
31  setEditable( true );
32  setInsertPolicy( QComboBox::NoInsert );
33  setCompleter( 0 );
34  connect( this, SIGNAL( activated( const QString & ) ), this, SLOT( fixupScale() ) );
35  connect( lineEdit(), SIGNAL( editingFinished() ), this, SLOT( fixupScale() ) );
36  fixupScale();
37 }
38 
40 {
41 }
42 
43 void QgsScaleComboBox::updateScales( const QStringList &scales )
44 {
45  QStringList myScalesList;
46  QString oldScale = currentText();
47 
48  if ( scales.isEmpty() )
49  {
50  QSettings settings;
51  QString myScales = settings.value( "Map/scales", PROJECT_SCALES ).toString();
52  if ( !myScales.isEmpty() )
53  {
54  myScalesList = myScales.split( "," );
55  }
56  }
57  else
58  {
59  QStringList::const_iterator scaleIt = scales.constBegin();
60  for ( ; scaleIt != scales.constEnd(); ++scaleIt )
61  {
62  myScalesList.append( *scaleIt );
63  }
64  }
65 
66  QStringList parts;
67  double denominator;
68  bool ok;
69  for ( int i = 0; i < myScalesList.size(); ++i )
70  {
71  parts = myScalesList[ i ] .split( ':' );
72  denominator = QLocale::system().toDouble( parts[1], &ok );
73  if ( ok )
74  {
75  myScalesList[ i ] = toString( 1.0 / denominator );
76  }
77  }
78 
79  blockSignals( true );
80  clear();
81  addItems( myScalesList );
82  setScaleString( oldScale );
83  blockSignals( false );
84 }
85 
87 {
88  QComboBox::showPopup();
89 
90  if ( !currentText().contains( ':' ) )
91  {
92  return;
93  }
94  QStringList parts = currentText().split( ':' );
95  bool ok;
96  int idx = 0;
97  int min = 999999;
98  long currScale = parts.at( 1 ).toLong( &ok );
99  long nextScale, delta;
100  for ( int i = 0; i < count(); i++ )
101  {
102  parts = itemText( i ).split( ':' );
103  nextScale = parts.at( 1 ).toLong( &ok );
104  delta = qAbs( currScale - nextScale );
105  if ( delta < min )
106  {
107  min = delta;
108  idx = i;
109  }
110  }
111 
112  blockSignals( true );
113  view()->setCurrentIndex( model()->index( idx, 0 ) );
114  blockSignals( false );
115 }
116 
119 {
120  return toString( mScale );
121 }
122 
124 bool QgsScaleComboBox::setScaleString( QString scaleTxt )
125 {
126  bool ok;
127  double newScale = toDouble( scaleTxt, &ok );
128  if ( ! ok )
129  {
130  return false;
131  }
132  else
133  {
134  mScale = newScale;
135  setEditText( toString( mScale ) );
136  clearFocus();
137  return true;
138  }
139 }
140 
143 {
144  return mScale;
145 }
146 
148 void QgsScaleComboBox::setScale( double scale )
149 {
150  setScaleString( toString( scale ) );
151 }
152 
154 void QgsScaleComboBox::fixupScale()
155 {
156  double newScale;
157  double oldScale = mScale;
158  bool ok, userSetScale;
159  QStringList txtList = currentText().split( ':' );
160  userSetScale = txtList.size() != 2;
161 
162  // QgsDebugMsg( QString( "entered with oldScale: %1" ).arg( oldScale ) );
163  newScale = toDouble( currentText(), &ok );
164 
165  // Valid string representation
166  if ( ok && ( newScale != oldScale ) )
167  {
168  // if a user types scale = 2345, we transform to 1:2345
169  if ( userSetScale && newScale >= 1.0 )
170  {
171  mScale = 1 / newScale;
172  }
173  else
174  {
175  mScale = newScale;
176  }
177  setScale( mScale );
178  emit scaleChanged();
179  }
180  else
181  {
182  // Invalid string representation or same scale
183  // Reset to the old
184  setScale( mScale );
185  }
186 }
187 
188 QString QgsScaleComboBox::toString( double scale )
189 {
190  if ( scale == 0 )
191  {
192  return "0";
193  }
194  else if ( scale > 1 )
195  {
196  return QString( "%1:1" ).arg( QLocale::system().toString( qRound( scale ) ) );
197  }
198  else
199  {
200  return QString( "1:%1" ).arg( QLocale::system().toString( qRound( 1.0 / scale ) ) );
201  }
202 }
203 
204 double QgsScaleComboBox::toDouble( QString scaleString, bool * returnOk )
205 {
206  bool ok = false;
207  QString scaleTxt( scaleString );
208 
209  double scale = QLocale::system().toDouble( scaleTxt, &ok );
210  if ( ok )
211  {
212  // Create a text version and set that text and rescan
213  // Idea is to get the same rounding.
214  scaleTxt = toString( scale );
215  }
216  // It is now either X:Y or not valid
217  ok = false;
218  QStringList txtList = scaleTxt.split( ':' );
219  if ( 2 == txtList.size() )
220  {
221  bool okX = false;
222  bool okY = false;
223  int x = QLocale::system().toInt( txtList[ 0 ], &okX );
224  int y = QLocale::system().toInt( txtList[ 1 ], &okY );
225  if ( okX && okY )
226  {
227  // Scale is fraction of x and y
228  scale = ( double )x / ( double )y;
229  ok = true;
230  }
231  }
232 
233  // Set up optional return flag
234  if ( returnOk )
235  {
236  *returnOk = ok;
237  }
238  return scale;
239 }
240 
241 
static unsigned index
virtual ~QgsScaleComboBox()
static double toDouble(QString scaleString, bool *ok=NULL)
Helper function to convert a scale string to double.
void setScale(double scale)
Function to set the selected scale from double.
double scale()
Function to read the selected scale as double.
const CORE_EXPORT QString PROJECT_SCALES
Definition: qgis.cpp:67
int min(int a, int b)
Definition: util.h:93
bool setScaleString(QString scaleTxt)
Function to set the selected scale from text.
static QString toString(double scale)
Helper function to convert a double to scale string.
void scaleChanged()
Signal is emitted when user has finished editing/selecting a new scale.
QString scaleString()
Function to read the selected scale as text.
QgsScaleComboBox(QWidget *parent=0)
void updateScales(const QStringList &scales=QStringList())