Picture

You can use a Picture control within Impact.

These can be used within a DBW or from COM using the IDialog interface.

DBW Picture Controls

This control can read/write images to BLOB columns in a database table.

• You cannot use the DRAWINGS.D_GEOMDATA or SYMBOLS.S_GEOMDATA columns.
• You can use the DRAWINGS.D_THUMB, SYMBOLS.S_THUMB, or LAYERS.L_THUMB columns – but they are forced to be read only. These get overridden at save time anyway, so there is no point making them writable.
• You can use the picture controls in both internal and external DBW’s.
• You can add multiple picture controls to the same DBW (for different columns) or to an IDialog.

The picture controls will also be displayed within the Impact Browser as read only controls.

Database Field Attributes - Picture

Display

Caption

Enter a caption to describe this field. This will appear on the database window form. The caption is optional; if no caption is specified then the control is left aligned with the form. This is useful for larger picture controls

Hint

Enter a hint that will be displayed when the cursor hovers over the entry field on the database window form.

Database Field

Field

From the drop-down list choose the required database field. This list will only contain those fields that are valid for the field type chosen above.

Field in layer table

This option is only visible if the particular database has the Table type PDB Layer Extra in the Database Table Structure. If this is the case the field drop-down list will contain appropriate field names from the LAYERS database table as well. Selecting one of those fields will cause this option to be automatically checked.

This option is required so that Impact can correctly store the data for fields in the LAYERS table. Also, so it can distinguish between a field with the same name being added to both the LAYERS and ONE_UP table, for example. When this option is checked the data is stored internally with the name LAYERS.L_FIELD rather than just L_FIELD as it would for ONE_UP columns.

Value cannot be modified (Read-only)

Switch this option on to make this field read-only.

Value is not required until drawing Save

Any non-nullable fields (see Can be empty in database entry windows on the Table Field form) can have this option set. This will allow you to close the database entry window even when nothing has been entered. However, you will not be allowed to save the project until something has been entered for this field.

Image

Image control size

From the drop-down list choose one of the following:-

• 16 x 16
• 32 x 32
• 64 x 64
• Small
• Medium
• Large
• Custom - This will enable the two extra boxes where you can enter the required size in pixels

Allowed formats

From the drop-down list, either select All Supported Image Formats or switch off the check-boxes against the formats you don't want to allow.

Storage format

Choose the storage format of the image. When the image is saved into the database BLOB this is the image format used. You can change this at any time and Impact will correctly load any previously stored images again. However, if you are going to use the image externally then you should choose an appropriate format and stick with it.

From the drop-down list choose one of the following:-

• JPEG
• Windows Bitmap
• Portable Network Graphics

Storage size

You can choose how the image is resized when stored.

From the drop-down list choose one of the following:-

• Original size - images will not be resized. In this case the user could choose a very large image.
• Scale to fixed size - resize all images to the specified width & height maintaining the original aspect ratio.
• Shrink to maximum size - shrink all images larger than width x height maintaining the original aspect ratio; all other images will not be resized and will retain their original size.

The final two options will enable the two extra boxes where you can enter the required size in pixels.

Hide Commands

When running the database window, if the mouse hovers over a Picture field the following commands are displayed:-

• Load image from file
• Save image to file
• Clear image
• Copy image to clipboard
• Paste image from clipboard
• View image in associated windows viewer

From this drop-down list you can choose which of these commands you don't want to appear.

Commands panel always visible

Switch this option on to make the above commands always appear, regardless of where the cursor is.

Read only Mode

The control will be in read only mode if the DBW is not in editing mode, or if embedded within the Impact Browser.

When in read-only mode you can Save, Copy and View the images assigned to the control as long as those commands haven’t been hidden.