More work on coloring columns. Refactor the template editor, add some documentation for the new template function first_non_empty, add help text to the configuration dialog.

src/calibre/gui2/dialogs/template_line_editor.py

@@ -8,7 +8,7 @@ __docformat__ = 'restructuredtext en'
 from PyQt4.Qt import (SIGNAL, QLineEdit)
 from calibre.gui2.dialogs.template_dialog import TemplateDialog
 
-class LineEditWithTextBox(QLineEdit):
+class TemplateLineEditor(QLineEdit):
 
     '''
     Extend the context menu of a QLineEdit to include more actions.

src/calibre/gui2/library/models.py

@@ -535,12 +535,10 @@ class BooksModel(QAbstractTableModel): # {{{
         return img
 
     def set_color_templates(self):
-        print 'here'
         self.column_color_map = {}
         for i in range(1,self.db.column_color_count+1):
             name = self.db.prefs.get('column_color_name_'+str(i))
             if name:
-                print name, self.db.prefs.get('column_color_template_'+str(i))
                 self.column_color_map[name] = \
                         self.db.prefs.get('column_color_template_'+str(i))
         self.refresh()

src/calibre/gui2/preferences/look_feel.py

@@ -6,7 +6,7 @@ __copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
 from PyQt4.Qt import (QApplication, QFont, QFontInfo, QFontDialog,
-        QAbstractListModel, Qt)
+        QAbstractListModel, Qt, QColor)
 
 from calibre.gui2.preferences import ConfigWidgetBase, test_widget, CommaSeparatedList
 from calibre.gui2.preferences.look_feel_ui import Ui_Form
@@ -159,12 +159,36 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         self.df_up_button.clicked.connect(self.move_df_up)
         self.df_down_button.clicked.connect(self.move_df_down)
 
+        self.color_help_text.setWordWrap(True)
+        self.color_help_text.setText('<p>' +
+                _('Here you can specify coloring rules for fields shown in the '
+                  'library view. Choose the field you wish to color, then '
+                  'supply a template that specifies the color to use.') +
+                 '</p><p>' +
+                _('The template must evaluate to one of the color names shown '
+                  'below. You can use any legal template expression. '
+                  'For example, you can set the title to always display in '
+                  'green using the template "green" (without the quotes). '
+                  'To show the title in blue if the book has the tag "Science '
+                  'Fiction", red if the book has the tag "Mystery", or black if '
+                  'the book has neither tag, use '
+                  '"{tags:switch(Science Fiction,blue,Mystery,red,)}" '
+                  'To show the title in green if it has one format, blue if it '
+                  'two formats, and red if more, use '
+                  "\"program:cmp(count(field('formats'),','), 2, 'green', 'blue', 'red')\"") +
+                               '</p><p>' +
+                _('Note: if you want to color a "custom column with a fixed set '
+                  'of values", it is possible and often easier to specify the '
+                  'colors in the column definition dialog. There you can '
+                  'provide a color for each value without using a template.')+ '</p>')
         choices = db.field_metadata.displayable_field_keys()
         choices.sort(key=sort_key)
         choices.insert(0, '')
         for i in range(1, db.column_color_count+1):
             r('column_color_name_'+str(i), db.prefs, choices=choices)
             r('column_color_template_'+str(i), db.prefs)
+        all_colors = [unicode(s) for s in list(QColor.colorNames())]
+        self.colors_box.setText(', '.join(all_colors))
 
     def initialize(self):
         ConfigWidgetBase.initialize(self)

src/calibre/gui2/preferences/look_feel.ui

@@ -416,72 +416,80 @@ then the tags will be displayed each on their own line.</string>
        <string>Column Coloring</string>
       </attribute>
       <layout class="QGridLayout" name="column_color_layout">
-       <item row="0" column="0">
+       <item row="1" column="0">
         <widget class="QLabel">
          <property name="text">
           <string>Column name</string>
          </property>
         </widget>
        </item>
-       <item row="0" column="1">
+       <item row="0" column="0" colspan="2">
+        <widget class="QLabel" name="color_help_text">
+        </widget>
+       </item>
+       <item row="1" column="1">
         <widget class="QLabel">
          <property name="text">
           <string>Selection template</string>
          </property>
         </widget>
        </item>
-       <item row="1" column="0">
+       <item row="2" column="0">
         <widget class="QComboBox" name="opt_column_color_name_1">
         </widget>
        </item>
-       <item row="1" column="1">
-        <widget class="LineEditWithTextBox" name="opt_column_color_template_1">
-        </widget>
-       </item>
-       <item row="2" column="0">
-        <widget class="QComboBox" name="opt_column_color_name_2">
-        </widget>
-       </item>
        <item row="2" column="1">
-        <widget class="LineEditWithTextBox" name="opt_column_color_template_2">
+        <widget class="TemplateLineEditor" name="opt_column_color_template_1">
         </widget>
        </item>
        <item row="3" column="0">
-        <widget class="QComboBox" name="opt_column_color_name_3">
+        <widget class="QComboBox" name="opt_column_color_name_2">
         </widget>
        </item>
        <item row="3" column="1">
-        <widget class="LineEditWithTextBox" name="opt_column_color_template_3">
+        <widget class="TemplateLineEditor" name="opt_column_color_template_2">
         </widget>
        </item>
        <item row="4" column="0">
-        <widget class="QComboBox" name="opt_column_color_name_4">
+        <widget class="QComboBox" name="opt_column_color_name_3">
         </widget>
        </item>
        <item row="4" column="1">
-        <widget class="LineEditWithTextBox" name="opt_column_color_template_4">
+        <widget class="TemplateLineEditor" name="opt_column_color_template_3">
         </widget>
        </item>
        <item row="5" column="0">
-        <widget class="QComboBox" name="opt_column_color_name_5">
+        <widget class="QComboBox" name="opt_column_color_name_4">
         </widget>
        </item>
        <item row="5" column="1">
-        <widget class="LineEditWithTextBox" name="opt_column_color_template_5">
+        <widget class="TemplateLineEditor" name="opt_column_color_template_4">
         </widget>
        </item>
-       <item row="10" column="0" colspan="2">
-        <spacer name="verticalSpacer_4">
-         <property name="orientation">
-          <enum>Qt::Vertical</enum>
+       <item row="6" column="0">
+        <widget class="QComboBox" name="opt_column_color_name_5">
+        </widget>
+       </item>
+       <item row="6" column="1">
+        <widget class="TemplateLineEditor" name="opt_column_color_template_5">
+        </widget>
+       </item>
+       <item row="20" column="0">
+        <widget class="QLabel">
+         <property name="text">
+          <string>Color names</string>
          </property>
-         <property name="sizeHint" stdset="0">
-          <size>
-           <width>690</width>
-           <height>283</height>
-          </size>
+        </widget>
+       </item>
+       <item row="21" column="0" colspan="2">
+        <widget class="QTextEdit" name="colors_box">
+         <property name="sizePolicy">
+          <sizepolicy vsizetype="Expanding" hsizetype="Expanding">
+           <horstretch>0</horstretch>
+           <verstretch>1</verstretch>
+          </sizepolicy>
          </property>
-        </spacer>
+        </widget>
        </item>
       </layout>
      </widget>
@@ -496,7 +504,7 @@ then the tags will be displayed each on their own line.</string>
    <header>calibre/gui2/complete.h</header>
   </customwidget>
   <customwidget>
-   <class>LineEditWithTextBox</class>
+   <class>TemplateLineEditor</class>
    <extends>QLineEdit</extends>
    <header>calibre/gui2/dialogs/template_line_editor.h</header>
   </customwidget>

src/calibre/gui2/preferences/plugboard.py

@@ -7,12 +7,12 @@ __docformat__ = 'restructuredtext en'
 
 import copy
 
-from PyQt4.Qt import Qt, QLineEdit, QComboBox, SIGNAL, QListWidgetItem
+from PyQt4.Qt import Qt, QComboBox, QListWidgetItem
 
 from calibre.customize.ui import is_disabled
 from calibre.gui2 import error_dialog, question_dialog
 from calibre.gui2.device import device_name_for_plugboards
-from calibre.gui2.dialogs.template_dialog import TemplateDialog
+from calibre.gui2.dialogs.template_line_editor import TemplateLineEditor
 from calibre.gui2.preferences import ConfigWidgetBase, test_widget
 from calibre.gui2.preferences.plugboard_ui import Ui_Form
 from calibre.customize.ui import metadata_writers, device_plugins
@@ -24,26 +24,6 @@ from calibre.library.server.content import plugboard_content_server_value, \
 from calibre.utils.formatter import validation_formatter
 
 
-class LineEditWithTextBox(QLineEdit):
-
-    '''
-    Extend the context menu of a QLineEdit to include more actions.
-    '''
-
-    def contextMenuEvent(self, event):
-        menu = self.createStandardContextMenu()
-        menu.addSeparator()
-
-        action_open_editor = menu.addAction(_('Open Editor'))
-
-        self.connect(action_open_editor, SIGNAL('triggered()'), self.open_editor)
-        menu.exec_(event.globalPos())
-
-    def open_editor(self):
-        t = TemplateDialog(self, self.text())
-        if t.exec_():
-            self.setText(t.textbox.toPlainText())
-
 class ConfigWidget(ConfigWidgetBase, Ui_Form):
 
     def genesis(self, gui):
@@ -107,7 +87,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         self.source_widgets = []
         self.dest_widgets = []
         for i in range(0, len(self.dest_fields)-1):
-            w = LineEditWithTextBox(self)
+            w = TemplateLineEditor(self)
             self.source_widgets.append(w)
             self.fields_layout.addWidget(w, 5+i, 0, 1, 1)
             w = QComboBox(self)

src/calibre/manual/template_lang.rst

@@ -234,6 +234,7 @@ The following functions are available in addition to those described in single-f
     * ``cmp(x, y, lt, eq, gt)`` -- compares x and y after converting both to numbers. Returns ``lt`` if x < y. Returns ``eq`` if x == y. Otherwise returns ``gt``.
     * ``divide(x, y)`` -- returns x / y. Throws an exception if either x or y are not numbers.
     * ``field(name)`` -- returns the metadata field named by ``name``.
+    * ``first_non_empty(value, value, ...) -- returns the first value that is not empty. If all values are empty, then the empty value is returned. You can have as many values as you want.
     * ``format_date(x, date_format)`` -- format_date(val, format_string) -- format the value, which must be a date field, using the format_string, returning a string. The formatting codes are::
     
         d    : the day as number without a leading zero (1 to 31)

src/calibre/utils/formatter_functions.py

@@ -562,6 +562,22 @@ class BuiltinBooksize(BuiltinFormatterFunction):
                 pass
         return ''
 
+class BuiltinFirstNonEmpty(BuiltinFormatterFunction):
+    name = 'first_non_empty'
+    arg_count = -1
+    doc = _('first_non_empty(value, value, ...) -- '
+            'returns the first value that is not empty. If all values are '
+            'empty, then the empty value is returned.'
+            'You can have as many values as you want.')
+
+    def evaluate(self, formatter, kwargs, mi, locals, *args):
+        i = 0
+        while i < len(args):
+            if args[i]:
+                return args[i]
+            i += 1
+        return ''
+
 builtin_add         = BuiltinAdd()
 builtin_assign      = BuiltinAssign()
 builtin_booksize    = BuiltinBooksize()
@@ -571,8 +587,9 @@ builtin_contains    = BuiltinContains()
 builtin_count       = BuiltinCount()
 builtin_divide      = BuiltinDivide()
 builtin_eval        = BuiltinEval()
-builtin_format_date = BuiltinFormat_date()
+builtin_first_non_empty = BuiltinFirstNonEmpty()
 builtin_field       = BuiltinField()
+builtin_format_date = BuiltinFormat_date()
 builtin_ifempty     = BuiltinIfempty()
 builtin_list_item   = BuiltinListitem()
 builtin_lookup      = BuiltinLookup()