Overlay

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Function

Name

This template is called Overlay in Wikipedia. It is called Overlay legend in Commons.

In Wikipedia Overlay legend and Legend overlay redirect to Overlay.

Purpose

Image overlay

Allows image numbered, textual number, or colour tag overlays to be positioned over an image to indicate particular features in the image.

Up to 30 overlays can be positioned over the image. Any overlay can be placed over the image up to 3 times, to indicate multiple locations of the same feature in the image.

Typical colours of overlays are as follows:

Color name	Example
red (default)	–
blue	–
green	–
brown	–
saddlebrown	–
yellow	–

The colour of each overlay can be individually set. Each overlay inherits its colour from the previous overlay, so only the first of any colour grouped overlays needs to have its colour set.

Each overlay is configurably wikilinkable by the template.

The overlays can be turned off by setting overlay to 'no', which will result in the only the image and legend being displayed. This is particularly useful when the image itself already includes the overlays and-or colour tagging. See Spider's main organs below for example.

Overlay legend

A legend of the text for each overlay is displayed by default, in 3 columns, under the image.

The legend can be turned off by setting the number of columns to '0'.

The legend can be grouped into groups of overlays, explicitly up to 6 groups. Each explicit legend grouping can optionally be given a title.

The number of overlay legend text items in each column is automatically balanced by the template across the columns within each legend grouping.

If the start overlay item for the first explicit grouping is after the first overlay item then the overlay text items from the first overlay up to but not including the first explicitly grouped overlay item are displayed as an untitled grouping before the first explicit group.

If an end overlay item is specified for any explicit grouping and there is no following explicit grouping, then the remainder of the overlay items are displayed as an untitled grouping after the last explicit group.

By setting the start of the first explicit grouping after the first overlay item and the end of the sixth explicit grouping before the last overlay item, effectively 8 groupings can be configured, the first and eighth being untitled.

Deficiences

Automatic column balancing

While the template will handle missing set overlay values at the start, that is the first overlay item does not have to be overlay1, the template treats intermediate missing overlays as though they exist for column balancing, and it does not allow for any text wrapped new lines within an overlay item's text.

Undeterminable legend start and ends

If legend titles are provided without a corresponding start or end and the template cannot explicitly determine one from an adjacent legend then it will "guess" and unexpected results might be produced, which might not be stable with any template updates.

Legend start and end ranges can be overlapped. This is either a deficiency or a feature depending on how you look at it. However, overlapping ranges might result in unexpected behaviour, which might not be stable with any template updates.

Double quotes in pop up tips for overlays

Double quotes, ", cannot be placed in overlay tips when form = text or when form = colour are used. To include a double quote use its HTML coding, ".

Double quotes are always allowed in the overlay, but if the overlay tip for that overlay is not set separately, the tip, which defaults to the same text as the overlay, will probably not display correctly. The overlay tip for an overlay with double quotes in it should always be set explicitly when form = text or when form = colour are used.

Usage

This is a colour/color friendly template. Either spelling can be used for any parameter value or any parameter name.

Skeleton

{{overlay
| image        = 
| width        = 
| height       = 
| columns      = 
| grid         = 
| link         = 
| legendbox    = 
| float        = 
| overlay      = 
| border       = 
| legend1title = 
| legend1start = 
| legend1end   = 
<!-- ...up to 6... -->
| overlay1form = 
| overlay1     = 
| overlay1colour = 
| overlay1tip  = 
| overlay1left = 
| overlay1top  = 
| overlay1link = 
<!-- ...up to 30... -->
}}

Editing grid and coordinates

To assist in determining the position of each overlay a coordinate grid showing from the left ordinates and from the top ordinates can be displayed by setting the grid parameter to yes:

| grid         = yes

The coordinate grid is 900 x 900, so if the image is set to be smaller than this, the page content may be off scrolled, etc. The presentation will return to normal when the grid parameter is removed or set to a value other than yes.

Note that the top ordinate is the position of the top of the overlay from the top of the image and the left ordinate is the left of the overlay from the left of the image.

Form = colour

When setting

| overlayNform = colour

then the overlays still use up numbered positions within the list of overlays. Accordingly, if using a mixture of image and-or text forms with colour forms, then gaps will appear in the number sequence where a colour form overlay is specified.

It might be generally best if colour form overlays are always set as the last overlays. See Spider's main organs below for example.

Full minimal skeleton

To assist editors, a full 30 overlays but minimal skeleton is provided below:

Full minimal skeleton

{{overlay |image = |width = |height = |grid = |overlay1 = |overlay1top = |overlay1left = |overlay2 = |overlay2top = |overlay2left = |overlay3 = |overlay3top = |overlay3left = |overlay4 = |overlay4top = |overlay4left = |overlay5 = |overlay5top = |overlay5left = |overlay6 = |overlay6top = |overlay6left = |overlay7 = |overlay7top = |overlay7left = |overlay8 = |overlay8top = |overlay8left = |overlay9 = |overlay9top = |overlay9left = |overlay10 = |overlay10top = |overlay10left = |overlay11 = |overlay11top = |overlay11left = |overlay12 = |overlay12top = |overlay12left = |overlay13 = |overlay13top = |overlay13left = |overlay14 = |overlay14top = |overlay14left = |overlay15 = |overlay15top = |overlay15left = |overlay16 = |overlay16top = |overlay16left = |overlay17 = |overlay17top = |overlay17left = |overlay18 = |overlay18top = |overlay18left = |overlay19 = |overlay19top = |overlay19left = |overlay20 = |overlay20top = |overlay20left = |overlay21 = |overlay21top = |overlay21left = |overlay22 = |overlay22top = |overlay22left = |overlay23 = |overlay23top = |overlay23left = |overlay24 = |overlay24top = |overlay24left = |overlay25 = |overlay25top = |overlay25left = |overlay26 = |overlay26top = |overlay26left = |overlay27 = |overlay27top = |overlay27left = |overlay28 = |overlay28top = |overlay28left = |overlay29 = |overlay29top = |overlay29left = |overlay30 = |overlay30top = |overlay30left = }}

Examples

Note: The data in these examples is not necessarily correct.

Brisbane (with grid turned on)

Wikitext for Brisbane example

{{overlay |image = BrisbaneRiver02 gobeirne.jpg |width = 900 |height = 675 |columns = 2 |grid = yes |overlay1 = [[Jack Pesch Bridge, Brisbane|Jack Pesch Bridge]], [[Walter Taylor Bridge, Brisbane|Walter Taylor Bridge]] (road) (left), [[Albert Bridge, Brisbane|Albert Bridge]] (rail) (center), unnamed bridge (rail) (right) |overlay1tip = Jack Pesch, Walter Taylor, Albert, unnamed bridges |overlay1top = 50 |overlay1left = 780 |overlay2 = Eleanor Schonell Bridge (Green Bridge) (pedestrians, pedal cycles, buses) |overlay2top = 250 |overlay2left = 445 |overlay2link = Eleanor Schonell Bridge, Brisbane |overlay3 = Merivale Bridge (rail) |overlay3tip = Merivale Bridge |overlay3top = 375 |overlay3left = 720 |overlay3link = Merivale Bridge, Brisbane |overlay4 = William Jolly Bridge (road) |overlay4tip = William Jolly Bridge |overlay4top = 390 |overlay4left = 703 |overlay4link = William Jolly Bridge, Brisbane |overlay5 = Victoria Bridge |overlay5top = 400 |overlay5left = 650 |overlay5link = Victoria Bridge, Brisbane |overlay6 = Captain Cook Bridge |overlay6top = 390 |overlay6left = 480 |overlay6link = Captain Cook Bridge, Brisbane |overlay7 = Story Bridge |overlay7top = 545 |overlay7left = 550 |overlay7link = Story Bridge, Brisbane |overlay8 = Pacific Motorway |overlay8top = 313 |overlay8left = 240 |overlay8link = Pacific Motorway (Brisbane–Brunswick Heads) |overlay9 = Suncorp Stadium (Lang Park) (Rugby league/Rugby Union/Soccer ground) |overlay9tip = Suncorp Stadium |overlay9top = 390 |overlay9left = 825 |overlay9link = Suncorp Stadium |overlay10colour = blue |overlay10 = Norman Creek |overlay10top = 505 |overlay10left = 205 |overlay10link = Norman Creek (Queensland) |overlay11 = Oxley Creek |overlay11top = 19 |overlay11left = 480 |overlay11link = Oxley Creek (Queensland) |overlay12 = Brisbane River |overlay12top1 = 100 |overlay12left1 = 489 |overlay12top2 = 575 |overlay12left2 = 280 |overlay12link = Brisbane River |overlay13colour = red |overlay13 = Indooroopilly Shoppingtown |overlay13top = 65 |overlay13left = 860 |overlay13link = Indooroopilly Shopping Centre |overlay14 = "The Gabba" (Woolloongabba cricket ground) |overlay14tip = The Gabba |overlay14top = 380 |overlay14left = 350 |overlay14link = Brisbane Cricket Ground |overlay15colour = green |overlay15 = South Bank arts and recreation precinct |overlay15tip = South Bank |overlay15top = 375 |overlay15left = 580 |overlay15link = South Bank Parklands |overlay16color = red |overlay16 = Central business district |overlay16top = 450 |overlay16left = 590 |overlay16link = Brisbane central business district |overlay17 = [[University of Queensland]] (UoQ) St Lucia Campus |overlat17tip = University of Queensland |overlay17top = 245 |overlay17left = 505 |overlay18color = green |overlay18 = City Botanic Gardens |overlay18top = 425 |overlay18left = 520 |overlay18link = Brisbane City Botanic Gardens |overlay19colour = red |overlay19 = [[Queensland University of Technology]] (QUT) Gardens Point Campus |overlay19tip = Queensland University of Technology |overlay19top = 390 |overlay19left = 515 |overlay20 = Goodwill Bridge (pedestrians and pedal cycles) |overlay20top = 375 |overlay20left = 522 |overlay20tip = Goodwill Bridge |overlay20link = Goodwill Bridge, Brisbane |overlay21 = Hospital |overlay21top = 600 |overlay21left = 750 |overlay22 = Mater Private Hospital |overlay22top = 325 |overlay22left = 460 |overlay22link = Mater Health Services |overlay23 = Roma Street Rail Station |overlay23top = 420 |overlay23left = 725 |overlay23link = Roma Street railway station, Brisbane |overlay24colour = green |overlay24 = Roma Street Parkland |overlay24top = 455 |overlay24left = 740 |overlay24link = Roma Street Parkland |overlay25 = New Farm Park |overlay25top = 575 |overlay25left = 325 |overlay25link = New Farm Park, Brisbane |overlay26 = Victoria Park Golf Course |overlay26top = 520 |overlay26left = 810 |overlay27colour = red |overlay27 = Royal National Association Exhibition Grounds |overlay27tip = RNA Exhibition Grounds |overlay27top = 625 |overlay27left = 700 |overlay27link = Ekka |overlay28 = Floating pedestrian concourse |overlay28top = 525 |overlay28left = 455 |overlay29 = Inner City Bypass (rail) (left) (road) (right) |overlay29tip = Inner City Bypass |overlay29top = 525 |overlay29left = 760 |overlay29link = Inner City Bypass, Brisbane |overlay30colour = green |overlay30 = Long Pocket Golf Course |overlay30top = 85 |overlay30left = 455 }}

Charlotte Pass Village

Wikitext for Charlotte Pass Village example

{{overlay |image = Charlotte Pass Village in August.jpg |width = 900 |height = 530 |legend1title = Accommodation and service buildings in Charlotte Pass Village |legend1start = 1 |overlay1 = Kosciuszko Chalet Hotel |overlay1top = 335 |overlay1left = 25 |overlay2 = Charlotte Pass Ski Centre |overlay2top = 344 |overlay2left = 330 |overlay3 = Bella Vista Staff Lodge (Cell Block, Cellavista) |overlay3top = 380 |overlay3left = 200 |overlay4 = Kosciuszko Alpine Club |overlay4top = 352 |overlay4left = 252 |overlay5 = Knockshannoch Lodge |overlay5top = 313 |overlay5left = 335 |overlay6 = Jerrabomberra Lodge |overlay6top = 300 |overlay6left = 300 |overlay7 = Spencer's Creek Lodge |overlay7top = 275 |overlay7left = 250 |overlay8 = Stillwell Lodge |overlay8top = 285 |overlay8left = 400 |overlay9 = Southern Alps Ski Lodge |overlay9top = 265 |overlay9left = 370 |overlay10 = Pygmy Possum Lodge |overlay10top = 245 |overlay10left = 305 |overlay11 = Snowbird Lodge |overlay11top = 250 |overlay11left = 439 |overlay12 = Arlberg Lodge |overlay12top = 260 |overlay12left = 489 |overlay13 = Burrawong Lodge |overlay13top = 266 |overlay13left = 512 |overlay14 = Alitji Lodge |overlay14top = 280 |overlay14left = 565 |overlay15 = Tar Gan Gil Lodge |overlay15top = 320 |overlay15left = 505 |legend2title = Other facilities and features (Guthries Poma (Platter lift) and Pulpit T-Bar not shown) |legend2start = 16 |overlay16 = Sewage plant (Shakespear's Lodge) |overlay16top = 245 |overlay16left = 45 |overlay17 = Basin Poma |overlay17top = 380 |overlay17left = 350 |overlay18 = Kosi Carpet (Magic Carpet (Moving carpet)) |overlay18top =350 |overlay18left = 450 |overlay19 = Kangaroo Ridge Triple Chairlift |overlay19top = 330 |overlay19left = 450 |overlay20 = "Fox hole" at the eastern end of Stillwell Ridge |overlay20top = 50 |overlay20left = 740 |overlay21 = Workshop |overlay21top = 313 |overlay21left = 240 }}

Spider's main organs (pre labelled image)

File:Spider main organs labelled.png

Spider's main organs 1 Fang (chelicera) 2 Venom gland 3 Brain 4 Pumping stomach 5 Forward aorta branch 6 Digestive cecum 7 Heart 8 Midgut 9 Malphigian tubules 10 Cloacal chamber 11 Rear aorta 12 Spinneret 13 Silk gland 14 Trachea 15 Ovary (female) 16 Book lung 17 Nerve cord 18 Legs 19 Pedipalp

Physiological systems    Nervous system    Digestive & excretory system    Circulatory system    Respiratory system    Reproductive system

Wikitext for Spider's Main Organs example

{{overlay |image = Spider main organs labelled.png |width = 350 |height = 259 |overlay = no |float = right |legend1title = Spider's main organs<ref name="izrfb">{{cite book |author=Ruppert, E.E. |author2=Fox, R.S. |author3=Barnes, R.D. |lastauthoramp=yes | title=Invertebrate Zoology | publisher=Brooks / Cole | edition=7 | isbn=0030259827 | date=2004 | pages=571-584 }}</ref> |legend1start = 1 |overlay1form = text |overlay1colour = black |overlay1 = Fang ([[chelicera]]) |overlay2 = [[Venom]] [[gland]] |overlay3 = [[Brain]] |overlay4 = Pumping [[stomach]] |overlay5 = Forward [[aorta]] branch |overlay6 = Digestive [[cecum]] |overlay7 = [[Heart]] |overlay8 = Midgut |overlay9 = [[Malphigian tubules]] |overlay10 = [[Cloaca]]l chamber |overlay11 = Rear [[aorta]] |overlay12 = [[Spinneret (spider)|Spinneret]] |overlay13 = [[Silk]] [[gland]] |overlay14 = [[invertebrate trachea|Trachea]] |overlay15 = [[Ovary]] (female) |overlay16 = [[Book lung]] |overlay17 = [[Dorsal nerve cord|Nerve cord]] |overlay18 = Legs |overlay19 = [[Pedipalp]] |legend2title = Physiological systems<ref name="izrfb"/> |legend2start = 20 |overlay20form = colour |overlay20color = blue |overlay20 = Nervous system |overlay21colour = #207326 |overlay21 = Digestive & excretory system |overlay22colour = #b51136 |overlay22 = Circulatory system |overlay23colour = #f5816a |overlay23 = Respiratory system |overlay24colour = yellow |overlay24 = Reproductive system }}

Template parameters

Parameter Name	Required	Description	Values
image	No	The image. If not set then only the legend is presented.	Image file name.
width	No	Width of the image in pixels. Defaults to 500.	Number.
height	No	Height of the image in pixels. Defaults to 500.	Number.
columns	No	The number of columns to display the legend in. Defaults to 3. Set to 0 to not display any legend.	Number == 0, 1, 2, 3, . . .
grid	No	Set to 'yes' to turn on the coordinate grid to allow easier determination of overlay coorindates while editing. Defaults to 'no'. All values other than 'yes' are equivalent to 'no'.	Template:Yes
link	No	Set to 'yes' to turn on default linking of overlay and legend entry. Defaults to 'no'. All values other than 'yes' are equivalent to 'no'.	Template:Yes
legendbox	No	Set to 'no' to turn off a box / border around each legend group set of overlays. Defaults to 'yes'. All other values other than 'no' are equivalent to 'yes'.	Text == no.
float	No	Floats the image and legend. Defaults to centering the image and legend on the page.	Text == right, left.
overlay	No	Determines whether or not the overlays are presented when an image is available. Defaults to 'yes'. All values other than 'no' are equivalent to 'yes'.	Text == no.
border	No	Determines whether or not a border is placed around the whole presentation. Defaults to 'yes'. All values other than 'no' are equivalent to 'yes'.	Text == no.
legend1title	No	Text for legend1 title.	Optionally linked text.
legend1start	No	The number of the first overlay to appear in legend1. Defaults to the first overlay set, otherwise to the previous legend end plus 1 if there is a previous legend.	Number == 1, . ., 30.
legend1end	No	The number of the last overlay to appear in legend1. Defaults to the next legend start less 1 if there is a next legend, otherwise to the last set overlay.	Number == 1, . ., 30.
	Both legend starts and legend ends do not need to be provided. Legend starts only, or, legend ends only, for each legend may be provided.
overlay1form	No	The form of the overlays. The default form is an image number, for example, . Other settings allow textual numbers, for example, 1, or coloured tags, for example,   . Defaults to the previous overlay form, or to 'image' if no previous overlay form.	Text == image, text, colour/color.
overlay1	No	Text for overlay1 for the legend. Defaults to overlay1tip if any.	Text. Do not link. The template will link.
overlay1colour	No	Colour of overlay1. Defaults to the previous overlay colour, or to 'red' if no previous overlay colour.	Text == red, green, blue.
overlay1tip	No	Pop up tool tip text to appear when the screen pointer is over overlay1. Defaults to overlay1.	Text.
overlay1left	No	Distance in pixels of the left edge of overlay1 from the left side of the image.	Number.
overlay1top	No	Distance in pixels of the top edge of overlay1 from the top side of the image.	Number.
overlay1link	No	Text to be used as a link for the overlay legend text. Defaults to overlay1 if link is not set to no.	Text. Do not link.
overlay1left1	No	The same as overlay1left.	As per overlay1left.
overlay1top1	No	The same as overlay1top.	As per overlay1top.
overlay1left2	No	The left ordinate for a second position of overlay1.	As per overlay1left.
overlay1top2	No	The top ordinate for a second position of overlay1.	As per overlay1top.
overlay1left3	No	The left ordinate for a third position of overlay1.	As per overlay1left.
overlay1top3	No	The top ordinate for a third position of overlay1.	As per overlay1top.

See also

• {{Annotated image}}, allows text notes to overlap image, allows cropping
• {{Site plan}}, to relatively position a marker image over a map image with selectable map, markers, and size
• {{Superimpose}}, absolutely position one image over another
• {{Superimpose2}}, to place up to 50 image layers over one another
• {{Location map}}, places a single image over another at a map coordinate location

References and notes