1 files changed, 461 insertions, 0 deletions

diff --git a/src/st/st-scroll-view-fade.c b/src/st/st-scroll-view-fade.c
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+++ b/src/st/st-scroll-view-fade.c
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+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+/*
+ * st-scroll-view-fade.h: Edge fade effect for StScrollView
+ *
+ * Copyright 2010 Intel Corporation.
+ * Copyright 2011 Adel Gadllah
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 2.1, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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 program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#include "st-private.h"
+#include "st-scroll-view-fade.h"
+#include "st-scroll-view.h"
+#include "st-widget.h"
+#include "st-theme-node.h"
+#include "st-scroll-bar.h"
+#include "st-scrollable.h"
+
+#include <clutter/clutter.h>
+#include <cogl/cogl.h>
+
+#define DEFAULT_FADE_OFFSET 68.0f
+
+#include "st-scroll-view-fade-generated.h"
+
+struct _StScrollViewFade
+{
+  ClutterShaderEffect parent_instance;
+
+  /* a back pointer to our actor, so that we can query it */
+  ClutterActor *actor;
+
+  StAdjustment *vadjustment;
+  StAdjustment *hadjustment;
+
+  guint fade_edges : 1;
+  guint extend_fade_area: 1;
+
+  ClutterMargin fade_margins;
+};
+
+G_DEFINE_TYPE (StScrollViewFade,
+               st_scroll_view_fade,
+               CLUTTER_TYPE_SHADER_EFFECT);
+
+enum {
+  PROP_0,
+
+  PROP_FADE_MARGINS,
+  PROP_FADE_EDGES,
+  PROP_EXTEND_FADE_AREA,
+
+  N_PROPS
+};
+
+static GParamSpec *props[N_PROPS] = { NULL, };
+
+static CoglTexture *
+st_scroll_view_fade_create_texture (ClutterOffscreenEffect *effect,
+                                    gfloat                  min_width,
+                                    gfloat                  min_height)
+{
+  CoglContext *ctx =
+    clutter_backend_get_cogl_context (clutter_get_default_backend ());
+
+  return COGL_TEXTURE (cogl_texture_2d_new_with_size (ctx, min_width, min_height));
+}
+
+static char *
+st_scroll_view_fade_get_static_shader_source (ClutterShaderEffect *effect)
+{
+   return g_strdup (st_scroll_view_fade_glsl);
+}
+
+
+static void
+st_scroll_view_fade_paint_target (ClutterOffscreenEffect *effect,
+                                  ClutterPaintNode       *node,
+                                  ClutterPaintContext    *paint_context)
+{
+  StScrollViewFade *self = ST_SCROLL_VIEW_FADE (effect);
+  ClutterShaderEffect *shader = CLUTTER_SHADER_EFFECT (effect);
+  ClutterOffscreenEffectClass *parent;
+
+  gdouble value, lower, upper, page_size;
+  ClutterActor *vscroll = st_scroll_view_get_vscroll_bar (ST_SCROLL_VIEW (self->actor));
+  ClutterActor *hscroll = st_scroll_view_get_hscroll_bar (ST_SCROLL_VIEW (self->actor));
+  gboolean h_scroll_visible, v_scroll_visible, rtl;
+
+  ClutterActorBox allocation, content_box, paint_box;
+
+  float fade_area_topleft[2];
+  float fade_area_bottomright[2];
+  graphene_point3d_t verts[4];
+
+  clutter_actor_get_paint_box (self->actor, &paint_box);
+  clutter_actor_get_abs_allocation_vertices (self->actor, verts);
+
+  clutter_actor_get_allocation_box (self->actor, &allocation);
+  st_theme_node_get_content_box (st_widget_get_theme_node (ST_WIDGET (self->actor)),
+                                (const ClutterActorBox *)&allocation, &content_box);
+
+  /*
+   * The FBO is based on the paint_volume's size which can be larger then the actual
+   * allocation, so we have to account for that when passing the positions
+   */
+  fade_area_topleft[0] = content_box.x1 + (verts[0].x - paint_box.x1);
+  fade_area_topleft[1] = content_box.y1 + (verts[0].y - paint_box.y1);
+  fade_area_bottomright[0] = content_box.x2 + (verts[3].x - paint_box.x2) + 1;
+  fade_area_bottomright[1] = content_box.y2 + (verts[3].y - paint_box.y2) + 1;
+
+  g_object_get (ST_SCROLL_VIEW (self->actor),
+                "hscrollbar-visible", &h_scroll_visible,
+                "vscrollbar-visible", &v_scroll_visible,
+                NULL);
+
+  if (v_scroll_visible)
+    {
+      if (clutter_actor_get_text_direction (self->actor) == CLUTTER_TEXT_DIRECTION_RTL)
+          fade_area_topleft[0] += clutter_actor_get_width (vscroll);
+
+      fade_area_bottomright[0] -= clutter_actor_get_width (vscroll);
+    }
+
+  if (h_scroll_visible)
+      fade_area_bottomright[1] -= clutter_actor_get_height (hscroll);
+
+  if (self->fade_margins.left < 0)
+    fade_area_topleft[0] -= ABS (self->fade_margins.left);
+  if (self->fade_margins.right < 0)
+    fade_area_bottomright[0] += ABS (self->fade_margins.right);
+  if (self->fade_margins.top < 0)
+    fade_area_topleft[1] -= ABS (self->fade_margins.top);
+  if (self->fade_margins.bottom < 0)
+    fade_area_bottomright[1] += ABS (self->fade_margins.bottom);
+
+  st_adjustment_get_values (self->vadjustment, &value, &lower, &upper, NULL, NULL, &page_size);
+  value = (value - lower) / (upper - page_size - lower);
+  clutter_shader_effect_set_uniform (shader, "fade_edges_top", G_TYPE_INT, 1, self->fade_edges ? value >= 0.0 : value > 0.0);
+  clutter_shader_effect_set_uniform (shader, "fade_edges_bottom", G_TYPE_INT, 1, self->fade_edges ? value <= 1.0 : value < 1.0);
+
+  st_adjustment_get_values (self->hadjustment, &value, &lower, &upper, NULL, NULL, &page_size);
+  value = (value - lower) / (upper - page_size - lower);
+  rtl = clutter_actor_get_text_direction (self->actor) == CLUTTER_TEXT_DIRECTION_RTL;
+  clutter_shader_effect_set_uniform (shader, "fade_edges_left", G_TYPE_INT, 1,
+                                     self->fade_edges ?
+                                     value >= 0.0 :
+                                     (rtl ? value < 1.0 : value > 0.0));
+  clutter_shader_effect_set_uniform (shader, "fade_edges_right", G_TYPE_INT, 1,
+                                     self->fade_edges ?
+                                     value <= 1.0 :
+                                     (rtl ? value > 0.0 : value < 1.0));
+
+  clutter_shader_effect_set_uniform (shader, "extend_fade_area", G_TYPE_INT, 1, self->extend_fade_area);
+  clutter_shader_effect_set_uniform (shader, "fade_offset_top", G_TYPE_FLOAT, 1, ABS (self->fade_margins.top));
+  clutter_shader_effect_set_uniform (shader, "fade_offset_bottom", G_TYPE_FLOAT, 1, ABS (self->fade_margins.bottom));
+  clutter_shader_effect_set_uniform (shader, "fade_offset_left", G_TYPE_FLOAT, 1, ABS (self->fade_margins.left));
+  clutter_shader_effect_set_uniform (shader, "fade_offset_right", G_TYPE_FLOAT, 1, ABS (self->fade_margins.right));
+  clutter_shader_effect_set_uniform (shader, "tex", G_TYPE_INT, 1, 0);
+  clutter_shader_effect_set_uniform (shader, "height", G_TYPE_FLOAT, 1, clutter_actor_get_height (self->actor));
+  clutter_shader_effect_set_uniform (shader, "width", G_TYPE_FLOAT, 1, clutter_actor_get_width (self->actor));
+  clutter_shader_effect_set_uniform (shader, "fade_area_topleft", CLUTTER_TYPE_SHADER_FLOAT, 2, fade_area_topleft);
+  clutter_shader_effect_set_uniform (shader, "fade_area_bottomright", CLUTTER_TYPE_SHADER_FLOAT, 2, fade_area_bottomright);
+
+  parent = CLUTTER_OFFSCREEN_EFFECT_CLASS (st_scroll_view_fade_parent_class);
+  parent->paint_target (effect, node, paint_context);
+}
+
+static void
+on_adjustment_changed (StAdjustment *adjustment,
+                       ClutterEffect *effect)
+{
+  gdouble value, lower, upper, page_size;
+  gboolean needs_fade;
+  StScrollViewFade *self = ST_SCROLL_VIEW_FADE (effect);
+
+  st_adjustment_get_values (self->vadjustment, &value, &lower, &upper, NULL, NULL, &page_size);
+  needs_fade = (value > lower + 0.1) || (value < upper - page_size - 0.1);
+
+  if (!needs_fade)
+    {
+      st_adjustment_get_values (self->hadjustment, &value, &lower, &upper, NULL, NULL, &page_size);
+      needs_fade = (value > lower + 0.1) || (value < upper - page_size - 0.1);
+    }
+
+  clutter_actor_meta_set_enabled (CLUTTER_ACTOR_META (effect), needs_fade);
+}
+
+static void
+st_scroll_view_fade_set_actor (ClutterActorMeta *meta,
+                               ClutterActor *actor)
+{
+  StScrollViewFade *self = ST_SCROLL_VIEW_FADE (meta);
+  ClutterActorMetaClass *parent;
+
+  g_return_if_fail (actor == NULL || ST_IS_SCROLL_VIEW (actor));
+
+  if (self->vadjustment)
+    {
+      g_signal_handlers_disconnect_by_func (self->vadjustment,
+                                            (gpointer)on_adjustment_changed,
+                                            self);
+      self->vadjustment = NULL;
+    }
+
+  if (self->hadjustment)
+    {
+      g_signal_handlers_disconnect_by_func (self->hadjustment,
+                                            (gpointer)on_adjustment_changed,
+                                            self);
+      self->hadjustment = NULL;
+    }
+
+
+  if (actor)
+    {
+        StScrollView *scroll_view = ST_SCROLL_VIEW (actor);
+        StScrollBar *vscroll = ST_SCROLL_BAR (st_scroll_view_get_vscroll_bar (scroll_view));
+        StScrollBar *hscroll = ST_SCROLL_BAR (st_scroll_view_get_hscroll_bar (scroll_view));
+        self->vadjustment = ST_ADJUSTMENT (st_scroll_bar_get_adjustment (vscroll));
+        self->hadjustment = ST_ADJUSTMENT (st_scroll_bar_get_adjustment (hscroll));
+
+        g_signal_connect (self->vadjustment, "changed",
+                          G_CALLBACK (on_adjustment_changed),
+                          self);
+
+        g_signal_connect (self->hadjustment, "changed",
+                          G_CALLBACK (on_adjustment_changed),
+                          self);
+
+        on_adjustment_changed (NULL, CLUTTER_EFFECT (self));
+    }
+
+  parent = CLUTTER_ACTOR_META_CLASS (st_scroll_view_fade_parent_class);
+  parent->set_actor (meta, actor);
+
+  /* we keep a back pointer here, to avoid going through the ActorMeta */
+  self->actor = clutter_actor_meta_get_actor (meta);
+}
+
+static void
+st_scroll_view_fade_dispose (GObject *gobject)
+{
+  StScrollViewFade *self = ST_SCROLL_VIEW_FADE (gobject);
+
+  if (self->vadjustment)
+    {
+      g_signal_handlers_disconnect_by_func (self->vadjustment,
+                                            (gpointer)on_adjustment_changed,
+                                            self);
+      self->vadjustment = NULL;
+    }
+
+  if (self->hadjustment)
+    {
+      g_signal_handlers_disconnect_by_func (self->hadjustment,
+                                            (gpointer)on_adjustment_changed,
+                                            self);
+      self->hadjustment = NULL;
+    }
+
+  self->actor = NULL;
+
+  G_OBJECT_CLASS (st_scroll_view_fade_parent_class)->dispose (gobject);
+}
+
+static void
+st_scroll_view_set_fade_margins (StScrollViewFade *self,
+                                 ClutterMargin    *fade_margins)
+{
+  if (self->fade_margins.left == fade_margins->left &&
+      self->fade_margins.right == fade_margins->right &&
+      self->fade_margins.top == fade_margins->top &&
+      self->fade_margins.bottom == fade_margins->bottom)
+    return;
+
+  self->fade_margins = *fade_margins;
+
+  if (self->actor != NULL)
+    clutter_actor_queue_redraw (self->actor);
+
+  g_object_notify_by_pspec (G_OBJECT (self), props[PROP_FADE_MARGINS]);
+}
+
+static void
+st_scroll_view_fade_set_fade_edges (StScrollViewFade *self,
+                                    gboolean          fade_edges)
+{
+  if (self->fade_edges == fade_edges)
+    return;
+
+  g_object_freeze_notify (G_OBJECT (self));
+
+  self->fade_edges = fade_edges;
+
+  if (self->actor != NULL)
+    clutter_actor_queue_redraw (self->actor);
+
+  g_object_notify_by_pspec (G_OBJECT (self), props[PROP_FADE_EDGES]);
+  g_object_thaw_notify (G_OBJECT (self));
+}
+
+static void
+st_scroll_view_fade_set_extend_fade_area (StScrollViewFade *self,
+                                          gboolean          extend_fade_area)
+{
+  if (self->extend_fade_area == extend_fade_area)
+    return;
+
+  self->extend_fade_area = extend_fade_area;
+
+  if (self->actor != NULL)
+    clutter_actor_queue_redraw (self->actor);
+
+  g_object_notify_by_pspec (G_OBJECT (self), props[PROP_EXTEND_FADE_AREA]);
+}
+
+static void
+st_scroll_view_fade_set_property (GObject *object,
+                                  guint prop_id,
+                                  const GValue *value,
+                                  GParamSpec *pspec)
+{
+  StScrollViewFade *self = ST_SCROLL_VIEW_FADE (object);
+
+  switch (prop_id)
+    {
+    case PROP_FADE_MARGINS:
+      st_scroll_view_set_fade_margins (self, g_value_get_boxed (value));
+      break;
+    case PROP_FADE_EDGES:
+      st_scroll_view_fade_set_fade_edges (self, g_value_get_boolean (value));
+      break;
+    case PROP_EXTEND_FADE_AREA:
+      st_scroll_view_fade_set_extend_fade_area (self, g_value_get_boolean (value));
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+st_scroll_view_fade_get_property (GObject *object,
+                                  guint prop_id,
+                                  GValue *value,
+                                  GParamSpec *pspec)
+{
+  StScrollViewFade *self = ST_SCROLL_VIEW_FADE (object);
+
+  switch (prop_id)
+    {
+    case PROP_FADE_MARGINS:
+      g_value_set_boxed (value, &self->fade_margins);
+      break;
+    case PROP_FADE_EDGES:
+      g_value_set_boolean (value, self->fade_edges);
+      break;
+    case PROP_EXTEND_FADE_AREA:
+      g_value_set_boolean (value, self->extend_fade_area);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+st_scroll_view_fade_class_init (StScrollViewFadeClass *klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+  ClutterShaderEffectClass *shader_class;
+  ClutterOffscreenEffectClass *offscreen_class;
+  ClutterActorMetaClass *meta_class = CLUTTER_ACTOR_META_CLASS (klass);
+
+  gobject_class->dispose = st_scroll_view_fade_dispose;
+  gobject_class->get_property = st_scroll_view_fade_get_property;
+  gobject_class->set_property = st_scroll_view_fade_set_property;
+
+  meta_class->set_actor = st_scroll_view_fade_set_actor;
+
+  shader_class = CLUTTER_SHADER_EFFECT_CLASS (klass);
+  shader_class->get_static_shader_source = st_scroll_view_fade_get_static_shader_source;
+
+  offscreen_class = CLUTTER_OFFSCREEN_EFFECT_CLASS (klass);
+  offscreen_class->create_texture = st_scroll_view_fade_create_texture;
+  offscreen_class->paint_target = st_scroll_view_fade_paint_target;
+
+  /**
+   * StScrollViewFade:fade-margins:
+   *
+   * The margins widths that are faded.
+   */
+  props[PROP_FADE_MARGINS] =
+    g_param_spec_boxed ("fade-margins",
+                        "Fade margins",
+                        "The margin widths that are faded",
+                        CLUTTER_TYPE_MARGIN,
+                        ST_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * StScrollViewFade:fade-edges:
+   *
+   * Whether the faded area should extend to the edges of the #StScrollViewFade.
+   */
+  props[PROP_FADE_EDGES] =
+    g_param_spec_boolean ("fade-edges",
+                          "Fade Edges",
+                          "Whether the faded area should extend to the edges",
+                          FALSE,
+                          ST_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * StScrollViewFade:extend-fade-area:
+   *
+   * Whether faded edges should extend beyond the faded area of the #StScrollViewFade.
+   */
+  props[PROP_EXTEND_FADE_AREA] =
+    g_param_spec_boolean ("extend-fade-area",
+                          "Extend Fade Area",
+                          "Whether faded edges should extend beyond the faded area",
+                          FALSE,
+                          ST_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY);
+
+  g_object_class_install_properties (gobject_class, N_PROPS, props);
+}
+
+static void
+st_scroll_view_fade_init (StScrollViewFade *self)
+{
+  self->fade_margins = (ClutterMargin) {
+    DEFAULT_FADE_OFFSET,
+    DEFAULT_FADE_OFFSET,
+    DEFAULT_FADE_OFFSET,
+    DEFAULT_FADE_OFFSET,
+  };
+}
+
+/**
+ * st_scroll_view_fade_new:
+ *
+ * Create a new #StScrollViewFade.
+ *
+ * Returns: (transfer full): a new #StScrollViewFade
+ */
+ClutterEffect *
+st_scroll_view_fade_new (void)
+{
+  return g_object_new (ST_TYPE_SCROLL_VIEW_FADE, NULL);
+}