/* GTK - The GIMP Toolkit * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald * * GtkAspectFrame: Ensure that the child window has a specified aspect ratio * or, if obey_child, has the same aspect ratio as its requested size * * Copyright Owen Taylor 4/9/97 * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library. If not, see . */ /* * Modified by the GTK+ Team and others 1997-2001. See the AUTHORS * file for a list of people on the GTK+ Team. See the ChangeLog * files for a list of changes. These files are distributed with * GTK+ at ftp://ftp.gtk.org/pub/gtk/. */ /** * SECTION:gtkaspectframe * @Short_description: A frame that constrains its child to a particular aspect ratio * @Title: GtkAspectFrame * * The #GtkAspectFrame is useful when you want * pack a widget so that it can resize but always retains * the same aspect ratio. For instance, one might be * drawing a small preview of a larger image. #GtkAspectFrame * derives from #GtkFrame, so it can draw a label and * a frame around the child. The frame will be * "shrink-wrapped" to the size of the child. */ #include "config.h" #include "gtkaspectframe.h" #include "gtksizerequest.h" #include "gtkprivate.h" #include "gtkintl.h" struct _GtkAspectFramePrivate { GtkAllocation center_allocation; gboolean obey_child; gfloat xalign; gfloat yalign; gfloat ratio; }; enum { PROP_0, PROP_XALIGN, PROP_YALIGN, PROP_RATIO, PROP_OBEY_CHILD }; static void gtk_aspect_frame_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec); static void gtk_aspect_frame_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec); static void gtk_aspect_frame_compute_child_allocation (GtkFrame *frame, GtkAllocation *child_allocation); #define MAX_RATIO 10000.0 #define MIN_RATIO 0.0001 G_DEFINE_TYPE_WITH_PRIVATE (GtkAspectFrame, gtk_aspect_frame, GTK_TYPE_FRAME) static void gtk_aspect_frame_class_init (GtkAspectFrameClass *class) { GObjectClass *gobject_class; GtkFrameClass *frame_class; gobject_class = (GObjectClass*) class; frame_class = (GtkFrameClass*) class; gobject_class->set_property = gtk_aspect_frame_set_property; gobject_class->get_property = gtk_aspect_frame_get_property; frame_class->compute_child_allocation = gtk_aspect_frame_compute_child_allocation; g_object_class_install_property (gobject_class, PROP_XALIGN, g_param_spec_float ("xalign", P_("Horizontal Alignment"), P_("X alignment of the child"), 0.0, 1.0, 0.5, GTK_PARAM_READWRITE)); g_object_class_install_property (gobject_class, PROP_YALIGN, g_param_spec_float ("yalign", P_("Vertical Alignment"), P_("Y alignment of the child"), 0.0, 1.0, 0.5, GTK_PARAM_READWRITE)); g_object_class_install_property (gobject_class, PROP_RATIO, g_param_spec_float ("ratio", P_("Ratio"), P_("Aspect ratio if obey_child is FALSE"), MIN_RATIO, MAX_RATIO, 1.0, GTK_PARAM_READWRITE)); g_object_class_install_property (gobject_class, PROP_OBEY_CHILD, g_param_spec_boolean ("obey-child", P_("Obey child"), P_("Force aspect ratio to match that of the frame's child"), TRUE, GTK_PARAM_READWRITE)); } static void gtk_aspect_frame_init (GtkAspectFrame *aspect_frame) { aspect_frame->priv = gtk_aspect_frame_get_instance_private (aspect_frame); aspect_frame->priv->xalign = 0.5; aspect_frame->priv->yalign = 0.5; aspect_frame->priv->ratio = 1.0; aspect_frame->priv->obey_child = TRUE; } static void gtk_aspect_frame_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec) { GtkAspectFrame *aspect_frame = GTK_ASPECT_FRAME (object); GtkAspectFramePrivate *priv = aspect_frame->priv; switch (prop_id) { /* g_object_notify is handled by the _frame_set function */ case PROP_XALIGN: gtk_aspect_frame_set (aspect_frame, g_value_get_float (value), priv->yalign, priv->ratio, priv->obey_child); break; case PROP_YALIGN: gtk_aspect_frame_set (aspect_frame, priv->xalign, g_value_get_float (value), priv->ratio, priv->obey_child); break; case PROP_RATIO: gtk_aspect_frame_set (aspect_frame, priv->xalign, priv->yalign, g_value_get_float (value), priv->obey_child); break; case PROP_OBEY_CHILD: gtk_aspect_frame_set (aspect_frame, priv->xalign, priv->yalign, priv->ratio, g_value_get_boolean (value)); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gtk_aspect_frame_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec) { GtkAspectFrame *aspect_frame = GTK_ASPECT_FRAME (object); GtkAspectFramePrivate *priv = aspect_frame->priv; switch (prop_id) { case PROP_XALIGN: g_value_set_float (value, priv->xalign); break; case PROP_YALIGN: g_value_set_float (value, priv->yalign); break; case PROP_RATIO: g_value_set_float (value, priv->ratio); break; case PROP_OBEY_CHILD: g_value_set_boolean (value, priv->obey_child); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } /** * gtk_aspect_frame_new: * @label: Label text. * @xalign: Horizontal alignment of the child within the allocation of * the #GtkAspectFrame. This ranges from 0.0 (left aligned) * to 1.0 (right aligned) * @yalign: Vertical alignment of the child within the allocation of * the #GtkAspectFrame. This ranges from 0.0 (top aligned) * to 1.0 (bottom aligned) * @ratio: The desired aspect ratio. * @obey_child: If %TRUE, @ratio is ignored, and the aspect * ratio is taken from the requistion of the child. * * Create a new #GtkAspectFrame. * * Returns: the new #GtkAspectFrame. */ GtkWidget* gtk_aspect_frame_new (const gchar *label, gfloat xalign, gfloat yalign, gfloat ratio, gboolean obey_child) { GtkAspectFrame *aspect_frame; GtkAspectFramePrivate *priv; aspect_frame = g_object_new (GTK_TYPE_ASPECT_FRAME, NULL); priv = aspect_frame->priv; priv->xalign = CLAMP (xalign, 0.0, 1.0); priv->yalign = CLAMP (yalign, 0.0, 1.0); priv->ratio = CLAMP (ratio, MIN_RATIO, MAX_RATIO); priv->obey_child = obey_child != FALSE; gtk_frame_set_label (GTK_FRAME(aspect_frame), label); return GTK_WIDGET (aspect_frame); } /** * gtk_aspect_frame_set: * @aspect_frame: a #GtkAspectFrame * @xalign: Horizontal alignment of the child within the allocation of * the #GtkAspectFrame. This ranges from 0.0 (left aligned) * to 1.0 (right aligned) * @yalign: Vertical alignment of the child within the allocation of * the #GtkAspectFrame. This ranges from 0.0 (top aligned) * to 1.0 (bottom aligned) * @ratio: The desired aspect ratio. * @obey_child: If %TRUE, @ratio is ignored, and the aspect * ratio is taken from the requistion of the child. * * Set parameters for an existing #GtkAspectFrame. */ void gtk_aspect_frame_set (GtkAspectFrame *aspect_frame, gfloat xalign, gfloat yalign, gfloat ratio, gboolean obey_child) { GtkAspectFramePrivate *priv; g_return_if_fail (GTK_IS_ASPECT_FRAME (aspect_frame)); priv = aspect_frame->priv; xalign = CLAMP (xalign, 0.0, 1.0); yalign = CLAMP (yalign, 0.0, 1.0); ratio = CLAMP (ratio, MIN_RATIO, MAX_RATIO); obey_child = obey_child != FALSE; if (priv->xalign != xalign || priv->yalign != yalign || priv->ratio != ratio || priv->obey_child != obey_child) { g_object_freeze_notify (G_OBJECT (aspect_frame)); if (priv->xalign != xalign) { priv->xalign = xalign; g_object_notify (G_OBJECT (aspect_frame), "xalign"); } if (priv->yalign != yalign) { priv->yalign = yalign; g_object_notify (G_OBJECT (aspect_frame), "yalign"); } if (priv->ratio != ratio) { priv->ratio = ratio; g_object_notify (G_OBJECT (aspect_frame), "ratio"); } if (priv->obey_child != obey_child) { priv->obey_child = obey_child; g_object_notify (G_OBJECT (aspect_frame), "obey-child"); } g_object_thaw_notify (G_OBJECT (aspect_frame)); gtk_widget_queue_resize (GTK_WIDGET (aspect_frame)); } } static void gtk_aspect_frame_compute_child_allocation (GtkFrame *frame, GtkAllocation *child_allocation) { GtkAspectFrame *aspect_frame = GTK_ASPECT_FRAME (frame); GtkAspectFramePrivate *priv = aspect_frame->priv; GtkBin *bin = GTK_BIN (frame); GtkWidget *child; gdouble ratio; child = gtk_bin_get_child (bin); if (child && gtk_widget_get_visible (child)) { GtkAllocation full_allocation; if (priv->obey_child) { GtkRequisition child_requisition; gtk_widget_get_preferred_size (child, &child_requisition, NULL); if (child_requisition.height != 0) { ratio = ((gdouble) child_requisition.width / child_requisition.height); if (ratio < MIN_RATIO) ratio = MIN_RATIO; } else if (child_requisition.width != 0) ratio = MAX_RATIO; else ratio = 1.0; } else ratio = priv->ratio; GTK_FRAME_CLASS (gtk_aspect_frame_parent_class)->compute_child_allocation (frame, &full_allocation); if (ratio * full_allocation.height > full_allocation.width) { child_allocation->width = full_allocation.width; child_allocation->height = full_allocation.width / ratio + 0.5; } else { child_allocation->width = ratio * full_allocation.height + 0.5; child_allocation->height = full_allocation.height; } child_allocation->x = full_allocation.x + priv->xalign * (full_allocation.width - child_allocation->width); child_allocation->y = full_allocation.y + priv->yalign * (full_allocation.height - child_allocation->height); } else GTK_FRAME_CLASS (gtk_aspect_frame_parent_class)->compute_child_allocation (frame, child_allocation); }