Change search restriction box to use grey help text. Remove label.

src/calibre/gui2/main.ui

@@ -123,17 +123,7 @@
        <number>0</number>
       </property>
       <item>
-       <widget class="QLabel" name="restriction_label">
-        <property name="text">
-         <string>&amp;Restrict to:</string>
-        </property>
-        <property name="buddy">
-         <cstring>search_restriction</cstring>
-        </property>
-       </widget>
-      </item>
-      <item>
-       <widget class="QComboBox" name="search_restriction">
+       <widget class="ComboBoxWithHelp" name="search_restriction">
         <property name="maximumSize">
          <size>
           <width>150</width>
@@ -543,6 +533,11 @@
    <extends>QComboBox</extends>
    <header>calibre.gui2.search_box</header>
   </customwidget>
+  <customwidget>
+   <class>ComboBoxWithHelp</class>
+   <extends>QComboBox</extends>
+   <header>calibre.gui2.widgets</header>
+  </customwidget>
   <customwidget>
    <class>ThrobbingButton</class>
    <extends>QToolButton</extends>

src/calibre/gui2/search_restriction_mixin.py

@@ -7,7 +7,8 @@ Created on 10 Jun 2010
 class SearchRestrictionMixin(object):
 
     def __init__(self):
-        self.search_restriction.activated[str].connect(self.apply_search_restriction)
+        self.search_restriction.initialize(help_text=_('Restrict To'))
+        self.search_restriction.activated[int].connect(self.apply_search_restriction)
         self.library_view.model().count_changed_signal.connect(self.restriction_count_changed)
         self.search_restriction.setSizeAdjustPolicy(self.search_restriction.AdjustToMinimumContentsLengthWithIcon)
         self.search_restriction.setMinimumContentsLength(10)
@@ -27,8 +28,8 @@ class SearchRestrictionMixin(object):
         if self.restriction_in_effect:
             self.set_number_of_books_shown()
 
-    def apply_search_restriction(self, r):
-        r = unicode(r)
+    def apply_search_restriction(self, i):
+        r = unicode(self.search_restriction.currentText())
         if r is not None and r != '':
             self.restriction_in_effect = True
             restriction = 'search:"%s"'%(r)

src/calibre/gui2/widgets.py

@@ -731,6 +731,58 @@ class HistoryLineEdit(QComboBox):
     def text(self):
         return self.currentText()
 
+class ComboBoxWithHelp(QComboBox):
+    '''
+    A combobox where item 0 is help text. CurrentText will return '' for item 0.
+    Be sure to always fetch the text with currentText. Don't use the signals
+    that pass a string, because they will not correct the text.
+    '''
+    def __init__(self, parent=None):
+        QComboBox.__init__(self, parent)
+        self.normal_background = 'rgb(255, 255, 255, 0%)'
+        self.connect(self, SIGNAL('currentIndexChanged(int)'), self.index_changed)
+        self.help_text = ''
+        self.state_set = False
+
+    def initialize(self, help_text=_('Search')):
+        self.help_text = help_text
+        self.set_state()
+
+    def set_state(self):
+        if not self.state_set:
+            if self.currentIndex() == 0:
+                self.setItemText(0, self.help_text)
+                self.setStyleSheet(
+                        'QComboBox { color: gray; background-color: %s; }' %
+                        self.normal_background)
+            else:
+                self.setItemText(0, '')
+                self.setStyleSheet(
+                        'QComboBox { color: black; background-color: %s; }' %
+                        self.normal_background)
+
+    def index_changed(self, index):
+        self.state_set = False
+        self.set_state()
+
+    def currentText(self):
+        if self.currentIndex() == 0:
+            return ''
+        return QComboBox.currentText(self)
+
+    def itemText(self, idx):
+        if idx == 0:
+            return ''
+        return QComboBox.itemText(self, idx)
+
+    def showPopup(self):
+        self.setItemText(0, '')
+        QComboBox.showPopup(self)
+
+    def hidePopup(self):
+        QComboBox.hidePopup(self)
+        self.set_state()
+
 class PythonHighlighter(QSyntaxHighlighter):
 
     Rules = []