Magnifier II is an image viewer. An image file dragged onto the widget's window is
displayed.
Magnifier II has a magnifier feature. A magnifying glass is displayed in the window.
Select a file by using the Choose File button, or drag an image file onto
the drop area of the window.
The image appears at full scale, but the window frame is, if necessary, constrained to fit
the computer’s display.
The pixel position of the mouse cursor can be displayed by clicking on the image.
The default size of the magnifier glass and the magnification factor can be set by using
the menu buttons at the top left of the window.
The magnifier lens type can also be chosen.
The magnifier can be dragged around the window with its handle.
The size of the magnifier glass and the magnification factor can be changed by using the sliders immediately above the displayed image.
The pixel position of the small cross at the centre of the glass is displayed whenever the
glass is moved.
Map images can be displayed in the usual way. When a matching World File is available it should also be read in.
Shift-clicking on the magnifier handle displays geographic coordinates in various formats. The geographic coordinates can be displayed in UTM eastings and northings, Lat/Long Degrees or in Lat/Long Degrees, Minutes and Seconds.
The UTM Zone and Hemisphere must be entered using the menus on the left of the window.
Waypoint names can be entered in the input field and can be recorded with the geographic coordinates in the text area below the map image.
To record a waypoint, enter its name in the input field then alt-click the magnifier handle.
The waypoint data (in JSON format) can be copied out of the text area and pasted into a file by the user for use in other programs.
The geographic coordinates can also be displayed and waypoints can also be recorded by shift-clicking or alt-clicking on the image, respectively.
The menus on the left of the window set default values which are used immediately and at the next load or reload of the webpage/widget. They are also preserved in cookies between runs of the widget (if cookies have been permitted).
The sliders immediately above the displayed image can be used to change the size of the magnifier glass and the magnification factor, but do not affect the default settings.
When a map image and a matching World File have been input, four additional menus appear on the left of the window. These, like the upper three menus, set default values which are used immediately and at the next load or reload of the webpage/widget. They are also preserved in cookies between runs of the widget (if cookies have been permitted).
These default values can be temporarily overridden by clicking on the star button (next to the blue help button) which opens the World File Map dialog. This provides menus to temporarily override the default settings.
The widget has on-screen alt- and shift- keys for use on computers that do not have a suitable keyboard. They are locking keys and are intended to be used when working with World Files, as described above. They do not effect typing in the waypoint input field.
This web widget is known to work correctly on macOS Sierra using the latest Safari and Firefox browsers and on the iPad using touch actions.
It may well work correctly on other desktop computers and browsers.
Behaviour on other tablet computers and mobile phones is not known.
The World Files feature may not be usable on tablet computers.
Dean Beedell
Coding and DocumentationThe Magnifier II web widget is Copyright © 2017 Dean Beedell and Harry Whitfield (G6AUC).
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA