vcs.maemo.org Git - hildon/blob - hildon-widgets/hildon-scroll-area.c

   1 /*
   2  * This file is part of hildon-libs
   3  *
   4  * Copyright (C) 2005 Nokia Corporation.
   5  *
   6  * Contact: Luc Pionchon <luc.pionchon@nokia.com>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public License
  10  * as published by the Free Software Foundation; either version 2.1 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  21  * 02110-1301 USA
  22  *
  23  */
  24
  25 /* hildon-scroll-area.c
  26  *
  27  */
  28
  29 #include "hildon-scroll-area.h"
  30 #include <gtk/gtkscrolledwindow.h>
  31 #include <gtk/gtkfixed.h>
  32 #include <gtk/gtkadjustment.h>
  33 #include <gtk/gtkwidget.h>
  34 #include <string.h>
  35
  36 typedef struct
  37   {
  38     GtkWidget *fixed;
  39     GtkWidget *swouter;
  40     GtkWidget *swinner;
  41     GtkWidget *child;
  42
  43     GtkAdjustment *outadj;
  44     GtkAdjustment *inadj;
  45
  46   } HildonScrollArea;
  47
  48
  49 static void hildon_scroll_area_outer_value_changed (GtkAdjustment *adjustment,
  50                                                     HildonScrollArea *sc);
  51 static void hildon_scroll_area_inner_value_changed (GtkAdjustment *adjustment,
  52                                                     HildonScrollArea *sc);
  53 static void hildon_scroll_area_size_allocate (GtkWidget *widget,
  54                                               GtkAllocation *allocation,
  55                                               HildonScrollArea *sc);
  56 static void hildon_scroll_area_child_requisition (GtkWidget *widget,
  57                                                   GtkRequisition *req,
  58                                                   HildonScrollArea *sc);
  59 static void hildon_scroll_area_fixed_allocate (GtkWidget *widget,
  60                                                GtkAllocation *allocation,
  61                                                HildonScrollArea *sc);
  62
  63 /**
  64  * hildon_scroll_area_new:
  65  * @sw: #GtkWidget - #GtkScrolledWindow
  66  * @child: #GtkWidget - Child to be place inside the sw
  67  *
  68  * This is not a widget. It's a helper function to provide
  69  * hildon specified scrolling for applications.
  70  * Puts and connects the @child to the @sw.
  71  * A common situation where the scroll area should be used
  72  * might be following.  A view containing @GtkTreeView based widget,
  73  * (or any similar widget which has built-in @GtkScrolledWindow support)
  74  * and eg. couple buttons.  Normaly @GtkScrolledWindow can not handle
  75  * the situation so that the @GtkTreeView built-in support
  76  * would work.  The scroll area is connecting this built-in system to
  77  * the scrolled window and also noticing the buttons.  To use, one should
  78  * create a box to which pack the buttons and the scroll area.
  79  * The scroll area then contains the problematic widget eg. the @GtkTreeView.
  80  * Then the box should be placed in the @GtkScrolledWindow.
  81  * The function is currently assuming that the newly created scroll area
  82  * hierarchy is not modified in anyway.  Or if it is, it may lead to
  83  * unwanted problems.  Also assumed, that the @child will be packed
  84  * to the @sw.
  85  *
  86  * Returns: a @GtkFixed
  87  */
  88 GtkWidget *hildon_scroll_area_new (GtkWidget *sw, GtkWidget *child)
  89 {
  90   GtkWidget *swi;
  91   GtkWidget *fixed;
  92   HildonScrollArea *sc;
  93
  94   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (sw)
  95                         && GTK_IS_WIDGET (child), NULL);
  96
  97   swi = gtk_scrolled_window_new (NULL, NULL);
  98   fixed = gtk_fixed_new ();
  99   sc = g_malloc (sizeof (HildonScrollArea));
 100   memset (sc, 0, sizeof (HildonScrollArea));
 101
 102   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (swi),
 103                                   GTK_POLICY_NEVER, GTK_POLICY_NEVER);
 104
 105   gtk_container_add (GTK_CONTAINER (swi), child);
 106   gtk_fixed_put (GTK_FIXED (fixed), swi, 0, 0);
 107
 108   sc->fixed = fixed;
 109   sc->swouter = sw;
 110   sc->swinner = swi;
 111   sc->child = child;
 112   sc->outadj = gtk_scrolled_window_get_vadjustment (GTK_SCROLLED_WINDOW (sw));
 113   sc->inadj = gtk_scrolled_window_get_vadjustment (GTK_SCROLLED_WINDOW (swi));
 114
 115   g_signal_connect_after (G_OBJECT (child), "size-request",
 116                           G_CALLBACK (hildon_scroll_area_child_requisition), sc);
 117
 118   g_signal_connect_after (G_OBJECT (sc->outadj), "value_changed",
 119                           G_CALLBACK (hildon_scroll_area_outer_value_changed), sc);
 120   g_signal_connect_after (G_OBJECT (sc->inadj), "value_changed",
 121                           G_CALLBACK (hildon_scroll_area_inner_value_changed), sc);
 122
 123   g_signal_connect_after (G_OBJECT (sw), "size-allocate",
 124                           G_CALLBACK (hildon_scroll_area_size_allocate), sc);
 125   g_signal_connect (G_OBJECT (sc->fixed), "size-allocate",
 126                     G_CALLBACK (hildon_scroll_area_fixed_allocate), sc);
 127   g_signal_connect_swapped (G_OBJECT (sw), "destroy",
 128                     G_CALLBACK (g_free), sc);
 129
 130   gtk_widget_show_all (sw);
 131   return fixed;
 132 }
 133
 134 static void hildon_scroll_area_fixed_allocate (GtkWidget *widget,
 135                                                GtkAllocation *allocation,
 136                                                HildonScrollArea *sc)
 137 {
 138   gtk_widget_set_size_request (sc->swinner, -1,
 139                                MIN (sc->outadj->page_size, allocation->height));
 140 }
 141
 142 static void hildon_scroll_area_child_requisition (GtkWidget *widget,
 143                                                   GtkRequisition *req,
 144                                                   HildonScrollArea *sc)
 145 {
 146   gint new_req = MAX (req->height, sc->fixed->allocation.height);
 147   gtk_widget_set_size_request (sc->fixed, -1, req->height);
 148   gtk_widget_set_size_request (sc->swinner, -1,
 149                                MIN (sc->outadj->page_size, new_req));
 150 }
 151
 152 static void hildon_scroll_area_outer_value_changed (GtkAdjustment *adjustment,
 153                                                     HildonScrollArea *sc)
 154 {
 155   GtkRequisition req;
 156   gtk_widget_size_request (sc->child, &req);
 157
 158   if ((sc->outadj->value + sc->outadj->page_size) > sc->fixed->allocation.y
 159       && sc->outadj->value < (sc->fixed->allocation.y + req.height))
 160     {
 161       gdouble new_pos = 0;
 162
 163       new_pos = MAX (sc->outadj->value - sc->fixed->allocation.y, 0);
 164       new_pos = MIN (new_pos, req.height - sc->inadj->page_size);
 165       new_pos = MAX (new_pos, 0);
 166
 167       gtk_fixed_move (GTK_FIXED (sc->fixed), sc->swinner, 0, new_pos);
 168       gtk_adjustment_set_value (sc->inadj, new_pos);
 169     }
 170 }
 171
 172 static void hildon_scroll_area_inner_value_changed (GtkAdjustment *adjustment,
 173                                                     HildonScrollArea *sc)
 174 {
 175   if (sc->outadj->value != sc->fixed->allocation.y + adjustment->value)
 176     gtk_adjustment_set_value (sc->outadj,
 177                               sc->fixed->allocation.y + adjustment->value);
 178 }
 179
 180 __inline__ static gint calculate_width (HildonScrollArea *sc)
 181 {
 182   GtkScrolledWindow *scwin = GTK_SCROLLED_WINDOW (sc->swouter);
 183   return (scwin->hscrollbar_visible * scwin->hscrollbar->allocation.width);
 184 }
 185
 186 static void hildon_scroll_area_size_allocate (GtkWidget *widget,
 187                                               GtkAllocation *allocation,
 188                                               HildonScrollArea *sc)
 189 {
 190   gtk_widget_set_size_request (sc->fixed, calculate_width (sc), sc->fixed->allocation.height);
 191   gtk_widget_set_size_request (sc->child, sc->fixed->allocation.width, -1);
 192 }