src/Dialogs/ComboPicker.cpp

   1 /*
   2 Copyright_License {
   3
   4   XCSoar Glide Computer - http://www.xcsoar.org/
   5   Copyright (C) 2000-2013 The XCSoar Project
   6   A detailed list of copyright holders can be found in the file "AUTHORS".
   7
   8   This program is free software; you can redistribute it and/or
   9   modify it under the terms of the GNU General Public License
  10   as published by the Free Software Foundation; either version 2
  11   of the License, or (at your option) any later version.
  12
  13   This program is distributed in the hope that it will be useful,
  14   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16   GNU General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with this program; if not, write to the Free Software
  20   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21 }
  22 */
  23
  24 #include "Dialogs/ComboPicker.hpp"
  25 #include "Dialogs/ListPicker.hpp"
  26 #include "Form/List.hpp"
  27 #include "Form/Edit.hpp"
  28 #include "Form/DataField/Base.hpp"
  29 #include "Form/DataField/ComboList.hpp"
  30 #include "Screen/Canvas.hpp"
  31 #include "Screen/Layout.hpp"
  32 #include "UIGlobals.hpp"
  33 #include "Look/DialogLook.hpp"
  34
  35 #include <assert.h>
  36
  37 static WndProperty *wComboPopupWndProperty;
  38 static DataField *ComboPopupDataField;
  39 static const ComboList *ComboListPopup;
  40
  41 class ComboPickerSupport : public ListItemRenderer {
  42   const ComboList &combo_list;
  43   const UPixelScalar padding;
  44
  45 public:
  46   ComboPickerSupport(const ComboList &_combo_list,
  47                      const UPixelScalar _padding)
  48     :combo_list(_combo_list), padding(_padding) {}
  49
  50
  51   virtual void OnPaintItem(Canvas &canvas, const PixelRect rc,
  52                            unsigned i) override {
  53     canvas.DrawClippedText(rc.left + padding,
  54                            rc.top + padding, rc,
  55                            combo_list[i].StringValueFormatted);
  56   }
  57 };
  58
  59 static const TCHAR*
  60 OnItemHelp(unsigned i)
  61 {
  62   if ((*ComboListPopup)[i].StringHelp)
  63     return (*ComboListPopup)[i].StringHelp;
  64
  65   return _T("");
  66 }
  67
  68 int
  69 ComboPicker(const TCHAR *caption,
  70             const ComboList &combo_list,
  71             ListHelpCallback_t help_callback,
  72             bool enable_item_help)
  73 {
  74   ComboListPopup = &combo_list;
  75
  76   const UPixelScalar font_height =
  77     UIGlobals::GetDialogLook().text_font->GetHeight() + Layout::FastScale(2);
  78   const UPixelScalar max_height = Layout::GetMaximumControlHeight();
  79   const UPixelScalar row_height = font_height >= max_height
  80     ? font_height
  81     /* this formula is supposed to be a compromise between too small
  82        and too large: */
  83     : (font_height + max_height) / 2;
  84
  85   const UPixelScalar padding = (row_height - font_height) / 2;
  86
  87   ComboPickerSupport support(combo_list, padding);
  88   return ListPicker(caption,
  89                     combo_list.size(),
  90                     combo_list.ComboPopupItemSavedIndex,
  91                     row_height,
  92                     support, false,
  93                     help_callback,
  94                     enable_item_help ? OnItemHelp : NULL);
  95 }
  96
  97 static void
  98 OnHelpClicked(unsigned i)
  99 {
 100   if (i < ComboListPopup->size()) {
 101     const ComboList::Item &item = (*ComboListPopup)[i];
 102     ComboPopupDataField->SetFromCombo(item.DataFieldIndex,
 103                                       item.StringValue);
 104   }
 105
 106   wComboPopupWndProperty->OnHelp();
 107 }
 108
 109 static int
 110 ComboPicker(const WndProperty &control,
 111             const ComboList &combo_list, bool EnableItemHelp)
 112 {
 113   return ComboPicker(control.GetCaption(), combo_list,
 114                      control.HasHelp() ? OnHelpClicked : nullptr,
 115                      EnableItemHelp);
 116 }
 117
 118 int
 119 dlgComboPicker(WndProperty *theProperty)
 120 {
 121   static bool bInComboPicker = false;
 122   bool bInitialPage = true;
 123   // used to exit loop (optionally reruns combo with
 124   // lower/higher index of items for int/float
 125   bool bOpenCombo = true;
 126
 127   // prevents multiple instances
 128   if (bInComboPicker)
 129     return 0;
 130
 131   bInComboPicker = true;
 132
 133   TCHAR sSavedInitialValue[100];
 134   int iSavedInitialDataIndex = -1;
 135
 136   while (bOpenCombo) {
 137     assert(theProperty != NULL);
 138     wComboPopupWndProperty = theProperty;
 139
 140     ComboPopupDataField = wComboPopupWndProperty->GetDataField();
 141     assert(ComboPopupDataField != NULL);
 142
 143     ComboListPopup = ComboPopupDataField->CreateComboList();
 144     if (bInitialPage) { // save values for "Cancel" from first page only
 145       bInitialPage = false;
 146       iSavedInitialDataIndex =
 147         (*ComboListPopup)[ComboListPopup->ComboPopupItemSavedIndex]
 148         .DataFieldIndex;
 149       ComboPopupDataField->CopyString(sSavedInitialValue, false);
 150     }
 151
 152     int idx = ComboPicker(*theProperty, *ComboListPopup, ComboPopupDataField->GetItemHelpEnabled());
 153
 154     bOpenCombo = false; //tell  combo to exit loop after close
 155
 156     if (idx >= 0 && (unsigned)idx < ComboListPopup->size()) {
 157       const ComboList::Item *item = &(*ComboListPopup)[idx];
 158
 159       // OK/Select
 160       if (item->DataFieldIndex == ComboList::Item::NEXT_PAGE) {
 161         // we're last in list and the want more past end of list so select last real list item and reopen
 162         ComboPopupDataField->SetDetachGUI(true);
 163         // we'll reopen, so don't call xcsoar data changed routine yet
 164         item = &(*ComboListPopup)[idx - 1];
 165         bOpenCombo = true; // reopen combo with new selected index at center
 166       } else if (item->DataFieldIndex == ComboList::Item::PREVIOUS_PAGE) {
 167         // same as above but lower items needed
 168         ComboPopupDataField->SetDetachGUI(true);
 169         item = &(*ComboListPopup)[idx + 1];
 170         bOpenCombo = true;
 171       }
 172
 173       ComboPopupDataField->SetFromCombo(item->DataFieldIndex,
 174                                         item->StringValue);
 175     } else {
 176       // Cancel
 177       // if we've detached the GUI during the load, then there is nothing to do here
 178       assert(iSavedInitialDataIndex >= 0);
 179       if (iSavedInitialDataIndex >= 0)
 180         // use statics here - saved from first page if multiple were used
 181         ComboPopupDataField->SetFromCombo(iSavedInitialDataIndex,
 182             sSavedInitialValue);
 183     }
 184
 185     delete ComboListPopup;
 186
 187     wComboPopupWndProperty->RefreshDisplay();
 188   } // loop reopen combo if <<More>>  or <<Less>> picked
 189
 190   bInComboPicker = false;
 191   return 1;
 192 }