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= Map view in JOSM =

This is the main view in JOSM (also called [https://en.wikipedia.org/wiki/Viewport Viewport]), where editing takes place, and Bing/Mapbox and other sources can be displayed.

[[Image(Help/MapView:MapView2.png,500,nolink)]]

=== What do you see here and when ===

There are several mechanisms in JOSM that affect what the user sees in the map view.

==== Visibility ====

* Data can be ''filtered out'' by [wikitr:/Help/Dialog/Filter Filters]
* [wikitr:/Help/Dialog/LayerList Layers (data, imagery)]
 * can be [wikitr:/Help/Dialog/LayerList#LayerButtons hidden] or can be set to [wikitr:/Help/Dialog/LayerList#VisibilityLayer semi-opaque]
 * can be obscured by other data layers ([wikitr:/Help/Dialog/LayerList#PanelButtons Up/Down buttons] are used to arrange layers)
* Map Paint Styles can hide OSM objects per zoom level

==== Appearance ====

* '''Partial fill of objects''' is enabled by default, it '''depends on area of the object'''. Areas will be fully filled if ''the partial fill would cover more than 50% of the area'' to avoid small unfilled gaps in the middle of an area.
* Enabled (in [wikitr:/Help/Preferences/Map#MapPaintStyles preferences]) and activated (in [wikitr:/Help/Dialog/MapPaint Map Paint Styles window] or preferences) styles affect what you see on the screen
* Styles can be displayed differently based on zoom factor

=== Map view controls ===

==== Move map ====

The area can be moved by '''holding down''' the {{{right mouse button}}}, and '''dragging''' the mouse. To improve dragging performance, labels are hidden while moving the map:

[[Image(Help/MapView:labels_hiding.gif,500)]]

This can be disabled in the [wikitr:/Help/Preferences/Display#OSMData OSM Data display settings].

==== Zoom ====

* Using the scroll wheel
* {{{+}}} and {{{-}}} keys 
* more specialized move/zoom actions and tools like:
 * several entries in the [wikitr:/Help/Menu/View View menu]
 * [wikitr:/Help/Action/JumpToPosition Jump To Position]
 * [wikitr:/Help/Action/Zoom Zoom tool]
 * [wikitr:/Help/Dialog/Minimap Minimap]

== Downloaded area ==

The area which was ''not'' downloaded is indicated by a yellow hatching. Ways which were downloaded can reach into the hatched area though. Make sure to edit only in the non hatched area because else it may lead to [wikitr:/Help/Concepts/Conflict conflicts] or duplicate data after upload.

Note that if you download filterd data (e.g. only buildings via [wikitr:/Help/Action/Download Overpass API]) there will be no hatched area at all as this is an incomplete data set. As soon as you download an additional area (containing all data in this area) into this layer the hatching will appear.

In special editing scenarios it may be useful to disable the hatching. This can be done via the [wikitr:/Help/Menu/View View menu] ([ExpertMode expert mode] only). Use this with caution. Only disable the hatching if you know what you are doing.

== Troubleshooting ==
=== MacOS ===
On a Mac with a one-button mouse, simulate right-click by holding down {{{Ctrl}}} while clicking the button.

== See also ==
* '''[wikitr:Action/Select Select Action]''' - help on selecting, moving, and rotating objects in the map view
* '''[wikitr:/Help/EditToolbar Modes]''' - overview of modes (frequently accessed tools) in JOSM
* [wikitr:/Help/StatusBar Status bar]
* [wikitr:/Help/Menu/ImageryContextMenu Imagery Context Menu]
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Back to [wikitr:/Help Main Help]