Cppcheck report - cdk-pixbuf (cppcheck 2.21.0-1): cdk-pixbuf/io-gdip-animation.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* CdkPixbuf library - animated gdip support
 *
 * Copyright (C) 1999 The Free Software Foundation
 *
 * Authors: Jonathan Blandford <jrb@redhat.com>
 *          Havoc Pennington <hp@redhat.com>
 *
 * 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 <http://www.gnu.org/licenses/>.
 */

#include <errno.h>

#include "io-gdip-native.h"
#include "io-gdip-animation.h"

G_GNUC_BEGIN_IGNORE_DEPRECATIONS

static void cdk_pixbuf_gdip_anim_finalize   (GObject        *object);

static gboolean                cdk_pixbuf_gdip_anim_is_static_image  (CdkPixbufAnimation *animation);
static CdkPixbuf*              cdk_pixbuf_gdip_anim_get_static_image (CdkPixbufAnimation *animation);

static void                    cdk_pixbuf_gdip_anim_get_size (CdkPixbufAnimation *anim,
                                                             int                *width,
                                                             int                *height);
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
static CdkPixbufAnimationIter* cdk_pixbuf_gdip_anim_get_iter (CdkPixbufAnimation *anim,
                                                             const GTimeVal     *start_time);
G_GNUC_END_IGNORE_DEPRECATIONS


G_DEFINE_TYPE (CdkPixbufGdipAnim, cdk_pixbuf_gdip_anim, CDK_TYPE_PIXBUF_ANIMATION);

static void
cdk_pixbuf_gdip_anim_init (CdkPixbufGdipAnim *anim)<--- Parameter 'anim' can be declared as pointer to const
{
}

static void
cdk_pixbuf_gdip_anim_class_init (CdkPixbufGdipAnimClass *klass)
{
        GObjectClass *object_class = G_OBJECT_CLASS (klass);
        CdkPixbufAnimationClass *anim_class = CDK_PIXBUF_ANIMATION_CLASS (klass);

        object_class->finalize = cdk_pixbuf_gdip_anim_finalize;

        anim_class->is_static_image = cdk_pixbuf_gdip_anim_is_static_image;
        anim_class->get_static_image = cdk_pixbuf_gdip_anim_get_static_image;
        anim_class->get_size = cdk_pixbuf_gdip_anim_get_size;
        anim_class->get_iter = cdk_pixbuf_gdip_anim_get_iter;
}

static void
cdk_pixbuf_gdip_anim_finalize (GObject *object)
{
        CdkPixbufGdipAnim *gdip_anim = CDK_PIXBUF_GDIP_ANIM (object);

        GList *l;
        CdkPixbufFrame *frame;
<--- The scope of the variable 'frame' can be reduced. [+]
The scope of the variable 'frame' can be reduced. Warning: Be careful when fixing this message, especially when there are inner loops. Here is an example where cppcheck will write that the scope for 'i' can be reduced:
void f(int x)
{
    int i = 0;
    if (x) {
        // it's safe to move 'int i = 0;' here
        for (int n = 0; n < 10; ++n) {
            // it is possible but not safe to move 'int i = 0;' here
            do_something(&i);
        }
    }
}
When you see this message it is always safe to reduce the variable scope 1 level.

        for (l = gdip_anim->frames; l; l = l->next) {
                frame = l->data;
                g_object_unref (frame->pixbuf);
                g_free (frame);
        }

        g_list_free (gdip_anim->frames);

        G_OBJECT_CLASS (cdk_pixbuf_gdip_anim_parent_class)->finalize (object);
}

static gboolean
cdk_pixbuf_gdip_anim_is_static_image  (CdkPixbufAnimation *animation)
{
        CdkPixbufGdipAnim *gdip_anim;

        gdip_anim = CDK_PIXBUF_GDIP_ANIM (animation);

        return (gdip_anim->frames != NULL &&
                gdip_anim->frames->next == NULL);
}

static CdkPixbuf*
cdk_pixbuf_gdip_anim_get_static_image (CdkPixbufAnimation *animation)
{
        CdkPixbufGdipAnim *gdip_anim;

        gdip_anim = CDK_PIXBUF_GDIP_ANIM (animation);

        if (gdip_anim->frames == NULL)
                return NULL;
        else
                return CDK_PIXBUF (((CdkPixbufFrame*)gdip_anim->frames->data)->pixbuf);
}

static void
cdk_pixbuf_gdip_anim_get_size (CdkPixbufAnimation *anim,
                              int                *width,
                              int                *height)
{
        CdkPixbufGdipAnim *gdip_anim;<--- Variable 'gdip_anim' can be declared as pointer to const

        gdip_anim = CDK_PIXBUF_GDIP_ANIM (anim);

        if (width)
                *width = gdip_anim->width;

        if (height)
                *height = gdip_anim->height;
}


static void
iter_clear (CdkPixbufGdipAnimIter *iter)
{
        iter->current_frame = NULL;
}

static void
iter_restart (CdkPixbufGdipAnimIter *iter)
{
        iter_clear (iter);

        iter->current_frame = iter->gdip_anim->frames;
}

G_GNUC_BEGIN_IGNORE_DEPRECATIONS
static CdkPixbufAnimationIter*
cdk_pixbuf_gdip_anim_get_iter (CdkPixbufAnimation *anim,
                              const GTimeVal     *start_time)
{
        CdkPixbufGdipAnimIter *iter;

        iter = g_object_new (CDK_TYPE_PIXBUF_GDIP_ANIM_ITER, NULL);

        iter->gdip_anim = CDK_PIXBUF_GDIP_ANIM (anim);

        g_object_ref (iter->gdip_anim);

        iter_restart (iter);

        iter->start_time = *start_time;
        iter->current_time = *start_time;
        iter->first_loop_slowness = 0;

        return CDK_PIXBUF_ANIMATION_ITER (iter);
}
G_GNUC_END_IGNORE_DEPRECATIONS

static void cdk_pixbuf_gdip_anim_iter_finalize   (GObject                   *object);

static int        cdk_pixbuf_gdip_anim_iter_get_delay_time             (CdkPixbufAnimationIter *iter);
static CdkPixbuf* cdk_pixbuf_gdip_anim_iter_get_pixbuf                 (CdkPixbufAnimationIter *iter);
static gboolean   cdk_pixbuf_gdip_anim_iter_on_currently_loading_frame (CdkPixbufAnimationIter *iter);
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
static gboolean   cdk_pixbuf_gdip_anim_iter_advance                    (CdkPixbufAnimationIter *iter,
                                                                       const GTimeVal         *current_time);
G_GNUC_END_IGNORE_DEPRECATIONS

G_DEFINE_TYPE (CdkPixbufGdipAnimIter, cdk_pixbuf_gdip_anim_iter, CDK_TYPE_PIXBUF_ANIMATION_ITER);

static void
cdk_pixbuf_gdip_anim_iter_init (CdkPixbufGdipAnimIter *iter)<--- Parameter 'iter' can be declared as pointer to const
{
}

static void
cdk_pixbuf_gdip_anim_iter_class_init (CdkPixbufGdipAnimIterClass *klass)
{
        GObjectClass *object_class = G_OBJECT_CLASS (klass);
        CdkPixbufAnimationIterClass *anim_iter_class =
                CDK_PIXBUF_ANIMATION_ITER_CLASS (klass);

        object_class->finalize = cdk_pixbuf_gdip_anim_iter_finalize;

        anim_iter_class->get_delay_time = cdk_pixbuf_gdip_anim_iter_get_delay_time;
        anim_iter_class->get_pixbuf = cdk_pixbuf_gdip_anim_iter_get_pixbuf;
        anim_iter_class->on_currently_loading_frame = cdk_pixbuf_gdip_anim_iter_on_currently_loading_frame;
        anim_iter_class->advance = cdk_pixbuf_gdip_anim_iter_advance;
}

static void
cdk_pixbuf_gdip_anim_iter_finalize (GObject *object)
{
        CdkPixbufGdipAnimIter *iter = CDK_PIXBUF_GDIP_ANIM_ITER (object);

        iter_clear (iter);

        g_object_unref (iter->gdip_anim);

        G_OBJECT_CLASS (cdk_pixbuf_gdip_anim_iter_parent_class)->finalize (object);
}

G_GNUC_BEGIN_IGNORE_DEPRECATIONS
static gboolean
cdk_pixbuf_gdip_anim_iter_advance (CdkPixbufAnimationIter *anim_iter,
                                  const GTimeVal         *current_time)
{
        CdkPixbufGdipAnimIter *iter;
        gint elapsed;
        gint loop;
        GList *tmp;
        GList *old;<--- Variable 'old' can be declared as pointer to const

        iter = CDK_PIXBUF_GDIP_ANIM_ITER (anim_iter);

        iter->current_time = *current_time;

        /* We use milliseconds for all times */
        elapsed =
          (((iter->current_time.tv_sec - iter->start_time.tv_sec) * G_USEC_PER_SEC +
            iter->current_time.tv_usec - iter->start_time.tv_usec)) / 1000;

        if (elapsed < 0) {
                /* Try to compensate; probably the system clock
                 * was set backwards
                 */
                iter->start_time = iter->current_time;
                elapsed = 0;
        }

        g_assert (iter->gdip_anim->total_time > 0);

        /* See how many times we've already played the full animation,
         * and subtract time for that.
         */

        if (iter->gdip_anim->loading)
                loop = 0;
        else {
                /* If current_frame is NULL at this point, we have loaded the
                 * animation from a source which fell behind the speed of the 
                 * display. We remember how much slower the first loop was due
                 * to this and correct the position calculation in order to not
                 * jump in the middle of the second loop.
                 */
                if (iter->current_frame == NULL)
                        iter->first_loop_slowness = MAX(0, elapsed - iter->gdip_anim->total_time);

                loop = (elapsed - iter->first_loop_slowness) / iter->gdip_anim->total_time;
                elapsed = (elapsed - iter->first_loop_slowness) % iter->gdip_anim->total_time;
        }

        iter->position = elapsed;

        /* Now move to the proper frame */
        if (iter->gdip_anim->loop == 0 || loop < iter->gdip_anim->loop)
                tmp = iter->gdip_anim->frames;
        else
                tmp = NULL;
        while (tmp != NULL) {
                CdkPixbufFrame *frame = tmp->data;<--- Variable 'frame' can be declared as pointer to const

                if (iter->position >= frame->elapsed &&
                    iter->position < (frame->elapsed + frame->delay_time))
                        break;

                tmp = tmp->next;
        }

        old = iter->current_frame;

        iter->current_frame = tmp;

        return iter->current_frame != old;
}
G_GNUC_END_IGNORE_DEPRECATIONS

int
cdk_pixbuf_gdip_anim_iter_get_delay_time (CdkPixbufAnimationIter *anim_iter)
{
        CdkPixbufFrame *frame;<--- Variable 'frame' can be declared as pointer to const
        CdkPixbufGdipAnimIter *iter;

        iter = CDK_PIXBUF_GDIP_ANIM_ITER (anim_iter);

        if (iter->current_frame) {
                frame = iter->current_frame->data;

#if 0
                g_print ("frame start: %d pos: %d frame len: %d frame remaining: %d\n",
                         frame->elapsed,
                         iter->position,
                         frame->delay_time,
                         frame->delay_time - (iter->position - frame->elapsed));
#endif

                return frame->delay_time - (iter->position - frame->elapsed);
        } else
                return -1; /* show last frame forever */
}

CdkPixbuf*
cdk_pixbuf_gdip_anim_iter_get_pixbuf (CdkPixbufAnimationIter *anim_iter)
{
        CdkPixbufGdipAnimIter *iter;
        CdkPixbufFrame *frame;<--- Variable 'frame' can be declared as pointer to const

        iter = CDK_PIXBUF_GDIP_ANIM_ITER (anim_iter);

        frame = iter->current_frame ? iter->current_frame->data : g_list_last (iter->gdip_anim->frames)->data;

#if 0
        if (FALSE && frame)
          g_print ("current frame %d dispose mode %d  %d x %d\n",
                   g_list_index (iter->gdip_anim->frames,
                                 frame),
                   frame->action,
                   cdk_pixbuf_get_width (frame->pixbuf),
                   cdk_pixbuf_get_height (frame->pixbuf));
#endif

        if (frame == NULL)
                return NULL;

        return frame->pixbuf;
}

static gboolean
cdk_pixbuf_gdip_anim_iter_on_currently_loading_frame (CdkPixbufAnimationIter *anim_iter)
{
        CdkPixbufGdipAnimIter *iter;

        iter = CDK_PIXBUF_GDIP_ANIM_ITER (anim_iter);

        return iter->current_frame == NULL || iter->current_frame->next == NULL;
}