images::ImagePage Class Reference

#include <image_page.h>

Collaboration diagram for images::ImagePage:

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Public Member Functions
	ImagePage (const std::string &p, const ImagePageAttrs &request)
	~ImagePage (void)
bool	render (void)
	Render image with specified request.
const ImagePageAttrs &	attributes () const
	Retrieve the attributes of render result.
const std::string &	get_path () const
	Retrieve the image path.
size_t	operator() (void) const
bool	operator== (const ImagePage &right)
bool	operator< (const ImagePage &right)
bool	operator> (const ImagePage &right)
int	length (void)
void	update_timestamp (void)
void	set_in_use_flag (bool flag)
bool	get_in_use_flag (void)
Static Public Member Functions
static int	max_zoom_factor ()
static int	min_zoom_factor ()
static size_t	calc_key (const std::string &anchor, int width, int height, float zoom, int rotation)
static void	calc_desired_dimension (ImagePageAttrs &request)
static gint64	estimate_length (const ImagePageAttrs &request)
static PluginRotationDegree	check_autorotate (int w, int h, int display_w, int display_h)

---

Detailed Description

Represent each image. Through this class, caller is able to

• Load a image.
• Check the image state is valid or not.
• Render a image with desired width, height and zoom factor.
• Rotate a image.
• Reference the raw image buffer. This class is designed to work in different thread, which means it can work in glib main thread or worker thread. But this class is not thread safety. The caller should make sure use it in thread safety environment.

Definition at line 108 of file image_page.h.

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Constructor & Destructor Documentation

images::ImagePage::ImagePage	(	const std::string &	p,
		const ImagePageAttrs &	request
	)

Definition at line 50 of file image_page.cpp.

References images::ImagePageAttrs::desired_color_depth, images::ImagePageAttrs::desired_height, images::ImagePageAttrs::desired_width, images::ImagePageAttrs::final_rotation, LOGPRINTF, images::ImagePageAttrs::original_height, images::ImagePageAttrs::original_width, images::ImagePageAttrs::rotation, and images::ImagePageAttrs::zoom.

: path(p)
, in_use(false)
, timestamp(0)
, loader(0)
, valid(false)
{
    LOGPRINTF("%s", p.c_str());
    
    attrs.original_width      = request.original_width;
    attrs.original_height     = request.original_height;
    attrs.desired_width       = request.desired_width;
    attrs.desired_height      = request.desired_height;
    attrs.desired_color_depth = request.desired_color_depth;

    attrs.zoom           = request.zoom;
    attrs.rotation       = request.rotation;
    attrs.final_rotation = request.final_rotation;

    display_width  = request.desired_width;
    display_height = request.desired_height;
}

images::ImagePage::~ImagePage

(

void

)

Definition at line 74 of file image_page.cpp.

References LOGPRINTF.

{
    LOGPRINTF("entry %s", path.c_str());

    destroy();
}

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Member Function Documentation

const ImagePageAttrs& images::ImagePage::attributes

(

)

const [inline]

Retrieve the attributes of render result.

Definition at line 120 of file image_page.h.

{ return attrs; }

void images::ImagePage::calc_desired_dimension

(

ImagePageAttrs &

request

)

[static]

Definition at line 125 of file image_page.cpp.

References check_autorotate(), Clockwise_Degrees_270, Clockwise_Degrees_360, Clockwise_Degrees_90, images::ImagePageAttrs::desired_height, images::ImagePageAttrs::desired_width, images::ImagePageAttrs::final_rotation, images::ImagePageAttrs::original_height, images::ImagePageAttrs::original_width, PLUGIN_ZOOM_TO_CROP_BY_PAGE, PLUGIN_ZOOM_TO_CROP_BY_WIDTH, PLUGIN_ZOOM_TO_PAGE, PLUGIN_ZOOM_TO_WIDTH, images::ImagePageAttrs::rotation, rotation, and images::ImagePageAttrs::zoom.

Referenced by estimate_length().

{
    int w = request.original_width;
    int h = request.original_height;
    unsigned int display_w = request.desired_width;
    unsigned int display_h = request.desired_height;
    
    PluginRotationDegree autorotate = check_autorotate(w, h, display_w, display_h);

    // TODO: Correct for autorotation, if needed.
    int rotation = static_cast<int>(request.rotation);
    rotation = (rotation + autorotate) % Clockwise_Degrees_360;
    request.final_rotation = static_cast<PluginRotationDegree>(rotation);
    if (   rotation == Clockwise_Degrees_90
        || rotation == Clockwise_Degrees_270)
    {
        w = request.original_height;
        h = request.original_width;
        request.original_width = w;
        request.original_height = h;
    }

    // Calculate the desired width and height.
    if (request.zoom == PLUGIN_ZOOM_TO_PAGE ||
        request.zoom == PLUGIN_ZOOM_TO_CROP_BY_PAGE)
    {
        float ratio_width = static_cast<float>(request.desired_width) /
                             static_cast<float>(w);

        float ratio_height = static_cast<float>(request.desired_height) /
                              static_cast<float>(h);

        if (ratio_width > ratio_height)
        {
            request.desired_width = static_cast<int>(ratio_height * w);
        }
        else
        {
            request.desired_height = static_cast<int>(ratio_width * h);
        }
    }
    else if (request.zoom == PLUGIN_ZOOM_TO_WIDTH ||
             request.zoom == PLUGIN_ZOOM_TO_CROP_BY_WIDTH)
    {
        float ratio_width = static_cast<float>(request.desired_width) /
                             static_cast<float>(w);
        request.desired_height = static_cast<int>(h * ratio_width);
    }
    else if (request.zoom > 0)
    {
        request.desired_width = static_cast<int>(
            static_cast<float>(request.zoom * w) / static_cast<float>(100));
        request.desired_height = static_cast<int>(
            static_cast<float>(request.zoom * h) / static_cast<float>(100));
    }
}

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size_t images::ImagePage::calc_key	(	const std::string &	anchor,
		int	width,
		int	height,
		float	zoom,
		int	rotation
	)			[static]

Definition at line 460 of file image_page.cpp.

References LOGPRINTF, make_hash_code(), and MAX_PATH_LEN.

Referenced by images::ImagesRenderer::get_page(), and operator()().

{
    struct PageKey
    {
        char   anchor[MAX_PATH_LEN]; 
        int    display_width;        // display size
        int    display_height;
        float  zoom;
        int    rotation;
    };

    PageKey key;
    int len = sizeof(PageKey);
    memset(&key, 0, len);
    
    memcpy(key.anchor, anchor.c_str(), strlen(anchor.c_str()));
    key.display_width = width;
    key.display_height = height;
    key.zoom = zoom;
    key.rotation = rotation;

    size_t h = make_hash_code((const char*)&key, len);

    LOGPRINTF("return %d", h);

    return h;
}

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PluginRotationDegree images::ImagePage::check_autorotate	(	int	w,
		int	h,
		int	display_w,
		int	display_h
	)			[static]

Definition at line 604 of file image_page.cpp.

References Clockwise_Degrees_0, Clockwise_Degrees_270, and Clockwise_Degrees_90.

Referenced by calc_desired_dimension().

{
    // Image fits on screen: no autorotation.
    if ((w <= display_w) && (h <= display_h))
    {
        return Clockwise_Degrees_0;
    }

    // Portrait image on landscape display: autorotate.
    if ((w < h) && (display_w > display_h))
    {
        return Clockwise_Degrees_270;
    }

    // Landscape image on portrait dislay: autorotate.
    if ((w > h) && (display_w < display_h))
    {
        return Clockwise_Degrees_90;
    }

    return Clockwise_Degrees_0;
}

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gint64 images::ImagePage::estimate_length

(

const ImagePageAttrs &

request

)

[static]

Definition at line 547 of file image_page.cpp.

References calc_desired_dimension(), images::ImagePageAttrs::desired_color_depth, images::ImagePageAttrs::desired_height, images::ImagePageAttrs::desired_width, images::ImageDither::get_rowstride(), LOGPRINTF, images::ImagePageAttrs::original_height, and images::ImagePageAttrs::original_width.

Referenced by images::ImagesRenderer::can_render().

{
    ImagePageAttrs attrs(request);

    calc_desired_dimension(attrs);

    // Memory size needed for bitmap to UDS.
    int rowstride = ImageDither::get_rowstride(attrs.desired_width, 
                                               attrs.desired_color_depth / 8,
                                               4);
    gint64 size_for_bitmap = static_cast<gint64>(rowstride) *
                             static_cast<gint64>(attrs.desired_height);

    // Memory size needed temporarily while rendering.
    gint64 size_for_tmp = size_for_bitmap * 5;

    // Memory size that must be available to render this image.
    gint64 size = size_for_bitmap + size_for_tmp;
    
    LOGPRINTF("original [%d %d] desired [%d %d] memory [%lld %lld %lld]",
              attrs.original_width, attrs.original_height,
              attrs.desired_width, attrs.desired_height,
              size_for_bitmap, size_for_tmp, size);
    
    return size;
}

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bool images::ImagePage::get_in_use_flag

(

void

)

[inline]

Definition at line 161 of file image_page.h.

{ return in_use; }

const std::string& images::ImagePage::get_path

(

)

const [inline]

Retrieve the image path.

Definition at line 123 of file image_page.h.

{ return path; }

int images::ImagePage::length

(

void

)

Definition at line 538 of file image_page.cpp.

References images::ImagePageAttrs::desired_height, LOGPRINTF, and images::ImagePageAttrs::row_stride.

Referenced by images::PagesCache::add_page(), and main().

{
    int size = attrs.row_stride * attrs.desired_height;
    
    LOGPRINTF("return %d", size);

    return size;
}

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static int images::ImagePage::max_zoom_factor

(

)

[inline, static]

Definition at line 125 of file image_page.h.

{ return 400; }

static int images::ImagePage::min_zoom_factor

(

)

[inline, static]

Definition at line 127 of file image_page.h.

{ return 10; }

size_t images::ImagePage::operator()

(

void

)

const

Definition at line 454 of file image_page.cpp.

References calc_key(), images::ImagePageAttrs::rotation, and images::ImagePageAttrs::zoom.

{
    return calc_key(path, display_width, display_height, 
                    attrs.zoom, attrs.rotation);
}

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bool images::ImagePage::operator<

(

const ImagePage &

right

)

Definition at line 511 of file image_page.cpp.

References LOGPRINTF.

{
   if (this->in_use && !right.in_use)
   {
       return false;
   }
   else if (!this->in_use && right.in_use)
   {
       return true;
   }
   else
   {
        LOGPRINTF("%ld < %ld ? %d", 
                this->timestamp, right.timestamp, 
                this->timestamp < right.timestamp);

        return (this->timestamp < right.timestamp);
   }
}

bool images::ImagePage::operator==

(

const ImagePage &

right

)

Definition at line 493 of file image_page.cpp.

References LOGPRINTF, images::ImagePageAttrs::rotation, and images::ImagePageAttrs::zoom.

{
    LOGPRINTF("entry");

    // Note: Ignore final_rotation for comparison
    if ((path == right.path)
        && (this->attrs.zoom == right.attrs.zoom)
        && (this->attrs.rotation == right.attrs.rotation)
        && (this->display_width == right.display_width)
        && (this->display_height == right.display_height))
    {
        return true;
    }

    return false;
}

bool images::ImagePage::operator>

(

const ImagePage &

right

)

Definition at line 532 of file image_page.cpp.

{
    return !((*this) < right);
}

bool images::ImagePage::render

(

void

)

Render image with specified request.

Definition at line 98 of file image_page.cpp.

References LOGPRINTF.

Referenced by images::ImageRenderTask::execute().

{
    LOGPRINTF("entry: anchor [%s]", anchor.c_str());

    if (!try_to_load_at_scale())
    {
        return false;
    }

    if (!update_attributes())
    {
        return false;
    }

    if (!try_to_dither())
    {
        return false;
    }

    if (!try_to_rotate_grey())
    {
        return false;
    }

    return true;
}

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void images::ImagePage::set_in_use_flag

(

bool

flag

)

[inline]

Definition at line 159 of file image_page.h.

Referenced by images::PluginRenderResultImpl::set_page(), and images::PluginRenderResultImpl::~PluginRenderResultImpl().

{ in_use = flag; }

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void images::ImagePage::update_timestamp

(

void

)

Definition at line 575 of file image_page.cpp.

Referenced by images::ImagesRenderer::notify_page_ready().

{
#ifdef WIN32
    timestamp = GetTickCount();
#else
    struct sysinfo s_info;
    sysinfo(&s_info);
    timestamp = s_info.uptime;
#endif
}

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The documentation for this class was generated from the following files:

• image_page.h
• image_page.cpp