2.7.4.2. Composite polygonal items: editing techniques

2.7.4.2.1. You can edit the shape of a polygon without changing its contents

To edit the shape of a polygon (without changing its contents):

  1. Select the item on the map. The attribute panel for the map item opens (for example, “Administrative division”).

  2. In the attribute panel that opens, click Edit .

    The item and attribute panel will switch to editing mode:

    Additionally, you will see a local toolbar that contains buttons (active buttons are orange, inactive buttons are white):

    • Indicate or change center of item. This button is only found in the local toolbar for items in the “Administrative division” category. For more information, see section 3.2.3. Drawing centers of administrative divisions.
    • Add external polygon. Launch the add external polygon mode (for the item you are editing).
    • Add internal polygon. Launch the add internal polygon mode (for the item you are editing).
    • Snapping mode. This button snaps the vertexes of the new item to neighboring polygons that were drawn earlier. This mode is used if, for example, you are drawing administrative divisions that have shared borders.
    • Polygon selection mode. This button is only available for items that consist of several polygons. It lets you switch between them and highlight the one you need.
    • Advanced mode. Advanced mode lets you edit an existing polygonal item and create new polygons that are part of it.

When you edit items consisting of several polygons:

  1. If the item you are editing consists of several polygons, then you will be asked to “Select a polygon to edit” when you click (Edit). This will also activate the button (Polygon selection mode):

    In this case you must click the appropriate polygon and it will open in editing mode:

2.7.4.2.2. Delete vertexes

You can delete a vertex that you positioned incorrectly. After you delete the vertex, you can continue editing the polygon.

To delete a vertex:

  1. Select the item on the map. The attribute panel for the map item opens (for example, “Administrative division”).

  2. In the attribute panel that opens, click Edit .

    The item and attribute panel will switch to editing mode:

  3. Click on the appropriate vertex to open the context menu. Then click Delete. The vertex you selected will be deleted. In its place will be a straight line connecting the vertexes that neighbor the one you deleted:

  4. Click Save. Your changes will be saved.

2.7.4.2.3. Add vertexes

You can add a vertex to correct your drawing of an item. After you add vertexes, you can continue editing the polygon.

To add vertexes:

  1. Select the item on the map. The attribute panel for the map item opens (for example, “Administrative division”).

  2. In the attribute panel that opens, click Edit .

    The item and attribute panel will switch to editing mode.

  3. Drag the point in the middle of two vertexes to the appropriate place. Release the mouse button to place the new vertex in the position you selected:

  4. Click Save. Your changes will be saved.

2.7.4.2.3. Make angle 90°.

You can make an angle 90° if you did not manage to draw a perfect right angle yourself. After you make the angles right, you can continue editing the polygon.

To make an angle 90°:

  1. Select the item on the map. The attribute panel for the map item opens (for example, “Administrative division”).

  2. In the attribute panel that opens, click Edit .

    The item and attribute panel will switch to editing mode:

  3. Select the appropriate vertex to open the context menu and then click Make angle 90°. The point you selected will become a right angle:

  4. Click Save. Your changes will be saved.

2.7.4.2.5. Round all corners

The general rules for drawing curved sections of items state that corners should be rounded. After you round your item's corners, you can continue editing it.

To round a corner (or all corners):

  1. Select the item on the map. The attribute panel for the map item opens (for example, Reservoir).

  2. In the attribute panel that opens, click Edit .

    The item and attribute panel will switch to editing mode:

  3. To round one corner: select the appropriate vertex to open the context menu and then click Round the corner. The selected angle will be rounded:

  4. To round all corners: click on any vertex to open the context menu. Then click Round all corners All angles of the polygon will be rounded:

  5. Click Save. Your changes will be saved.

2.7.4.2.6. Edit internal polygon

Attention.

When drawing internal polygons, follow 2.7.2. Rules for using internal polygons.

To edit the shape of an internal polygon:

  1. Select the item on the map. The attribute panel for the map item opens (for example, “Woodlands”).

  2. In the attribute panel that opens, click Edit .

    A local toolbar will open:

    Click (Polygon selection mode) in the local toolbar.

    Select the (internal) polygonal item. The item and attribute panel will switch to editing mode.

    The local toolbar contains buttons (active buttons are orange, inactive buttons are white):

    • Dragging mode. Launches dragging mode, which lets you drag the polygon to a new position without changing its shape. When you drag the polygon, make sure not to disrupt the relative positioning of the internal and external polygons: the internal polygon can't intersect with the borders of the external one.
    • Redraw. Deletes the internal polygon (but leaves its outline visible) and lets you re-draw it.
    • Polygon selection mode. This button is only available for items that consist of several polygons. It lets you switch between them and highlight the one you need (see section 2.7.4.5).
    • Snapping mode. This button snaps the vertexes of the new item to neighboring polygons that were drawn earlier. This mode is used if, for example, you are drawing administrative divisions that have shared borders.
    • Advanced mode. Advanced mode lets you edit an existing polygonal item and create new polygons that are part of it.
  3. Edit a polygon:

    1. Edit the shape of the selected polygon similarly to how you edit the shapes of other polygons. See sections 2.7.4.2.1, 2.7.4.2.2.

    2. Delete the selected polygon by clicking  Delete polygon .

    3. Drag the selected polygon by clicking  Drag .

    4. Redraw the selected polygon by clicking  Redraw .

  4. Click Save. Your changes will be saved.

2.7.4.2.7. Special concerns when editing items consisting of several polygons

When you edit items consisting of several polygons:

  1. Before your item will switch to (Editing mode) after you click , you will be asked to “Select a polygon to edit”. This will also activate the button (Polygon selection mode) in the local toolbar:

    In this case, you must click the appropriate polygon and it will open in editing mode:

  2. "Editing" primarily refers to the alteration of the item's shape. The techniques are the same as those described in sections 2.7.4.2.1 and 2.7.4.2.2.

  3. When you click (Delete) the selected polygon will be deleted.

    You can delete a polygonal item if it consists of at least one polygon. If you delete the last polygon of an item, you will also delete the item itself (for more on deleting items, see 2.10.6. Item: undo edit, report to moderator, delete item; get link to item)

  4. Click Advanced mode on the local toolbar to switch to the mode where you can add a new polygon to an item. The following buttons will be added to the toolbar:

    • Add/exclude existing sections mode. When this mode is active, clicking on sections of the border will either add them to the map item or exclude them from it.
    • Draw new polygon sections mode. When this mode is active, you can draw new polygon sections.

    You can use these sections to edit an item's contents.

    Attention.

    When drawing internal polygons, follow 2.7.2. Rules for using internal polygons.

2.7.4.2.8. Merge items by deleting the borders between them

In some cases you may need to join (merge) two or more polygons into one and delete the borders between them. For example, this may be necessary it you are drawing a river using a polygon (see 10.1.3.5).

Lets say that you outlined part of the river but haven't drawn the entire polygon yet:

You can add a new polygon to the part you drew by deleting the border between them.

To do this:

  1. Select the river polygon that you drew and click Edit in the attribute panel that opens.

  2. In the local toolbar that opens, click Advanced mode and finish drawing the river polygon (draw a new polygon that is contiguous with the one that was already drawn):

  3. In the local toolbar, click Add/exclude existing sections mode and exclude shared segments of the old and new polygon:

  4. Click Save.

After you save it, you will have one single river polygon:

If you join the river polygons and then delete the borders between them, you can turn the river (or another item that you need to merge polygons to form) into one polygonal item.

2.7.4.2.9. Split a polygon into parts

There are several reasons why you may need to split a polygon into parts. For example, you may need to select different types of vegetation polygons. After you divide the polygon, you can continue editing.

Lets say that you need to distinguish a cemetery (red arrow) from the woodlands surrounding it (green arrow):

To divide a polygon into parts:

  1. Click Create and select the appropriate item type (“Cemetery”).

    Create a new section of border in the spot where the existing polygon should be divided:

  2. Click (Add/exclude existing sections mode).

    Add the sections of border that should form part of the new polygon (i.e. the cemetery) to the new section of border:

  3. Save the new item:

  4. Select the old polygon (woodlands) on the map. Tap Edit . The item will switch to editing mode.

  5. Click Advanced mode .

    The polygon will switch to advanced editing mode.

  6. Click Add/exclude existing sections mode .

    Exclude the sections of border that are transferring to the new polygon (the cemetery):

  7. Add the new section of border (the one that separates the new polygon from the old one) to the old item:

  8. Save the old polygon (woodlands) with its new borders:

This way you will have two adjacent vegetation items: woodlands (green arrow) and cemetery (red arrow):