.: Operation modes :.

buttons operation

In this section it is presented the principles of iGeom, given an overview about the system.
The iGeom could be used in two different ways, as an applicative or as an applet (the could be used inside a Web browser), as explained into the section .
The iGeom has 3 (in applet) or 4 (in applicative) main areas, the figure 1 shows the applicative version with: the menu bar at its top, just bellow there is the buttons bar (which is composed by the primary bar and the secondary bar), in its central portion (the biggest one) there is the drawing/working area and in its inferior portion there is the messages bar.
Menu bar gives access to file operations, in its first option. All other options are available under the buttons bar, actually, several buttons bar options are not presented into the menu bar. The file options are not allowed into the applet version because of security reasons: in order to avoid a malicious applet to have access to the user's files.

Figura 1: main iGeom interface, in the applicative form, in its superior portion there is the menu bar.

Summary: the biggest difference between applicative and applet version of iGeom is that in the last one, due to the security restrictions of Java, it is not possible to get direct access to the file system of the computer.

Primary and secondary buttons

The buttons bar are divided in two rows, at the top there is the primary bar, with its primary buttons, and immediately bellow it there is the secondary bar with its secondary buttons.
Most of the primary buttons has no action, but to allow access to its secondary list of buttons. For example, the primary button straight lines , gives access to the secondary row related to straight line, like those to create segments, rays and lines.
At the present version, there are only 3 primary buttons that has no secondary row of buttons: (intersection points), (selector) and (move). The figure 2 presents the superior portion of the iGeom interface, showing the primary and the secondary bar associated to the subject creation of straight lines.

Figura 2: primary buttons and the secondary one related to the creation of straight lines.

For instance, to create a segment, it must be visible the secondary bar related to lines creation, if it isn't visible, it is necessary to "click" on the primary button (Create straight objects: line, semi-line, segment, parallel or perpendicular). Then the user must "click" on the segment constructor button (Draw segment...), that will be highlighted by a shadow (see figure 1), indicating the this is the active button. After this action, if the user "click" on an existent point A and then "click" on the point B, as a result, it will be create the segment AB into the drawing area.
This is one of two procedures to create an object with iGeom. These mode of objet creation, will be called here by action+selection. The other creation mode is the selection+action mode. Both of them are explained bellow.

Summary: Usually a primary button gives acces to its associated secondary buttons. Every time the user "click" on a primary button (with a secondary row), its secondary list of buttons will be presented. In the secondary row, the button that appears with a shadow is the active one, meaning that this is the "constructor" available to produce some object into the drawing area.

Operations modes: choosing first the operands or the operators

There are two operational modes to create objects into the iGeom, the difference between them is the order that an operand (the objects) or an operator (the objects constructor) is selected. If the operands are first selected, the it is called here by selection+action, on the other hand, it the operator is first selected, then is is called by action+selection. These two modes are
  1. action+selection: initially the user must choose the action, "clicking" on a button associated with some construction operation (for instance, the point or the line constructor) and then the user must select the adequated objects ("clicking" on them).
    Example: The construction of two points and the segment joining them.
    Initially, the user must activate the action related to the point creation (Create point in the drawing area or on object) by clicking on the button . After this, the user must "click" on the drawing are twice, on the position that each point must be created (we will be supposed labeled by A and B).
    The next step is to "click" on the primary button for straight lines , which activate the secondary button responsible for lines.
    If the secondary button for segments isn't activated, "click" on it. Now "click" the point A, release the "mouse" button, move it to the point B (during this movement it will be shown temporary segments), when the point B becomes yellow (otherwise a NEW point will be created, producing a segment that is independent of B), give another "click". There it is, the segment AB is created, this menas that: whenever point A or B is moved, the segment is automatically updated by iGeom, preserving the relation between the segment and both given points.
    This is the most important feature of any Interactive Geometry software: the movement of points and the automatic update of other related objects, preserving existent properties between them.
  2. selection+action: initially the geometric objects must be selected, then it must be chosen the action.
    In order to select/mark any geometric object, the primary button selector must be activated. After the objects selection, they must became in yellow color (the default color could be changed with a "right click" in "mouse"), then the action must be chosen (with a "click" on the corresponding button).
    Example: How to construct two points and a segment linking them both.
    The construction of free points is only possible under the action+selection mode. Let's suppose that the two points is already available in drawing area (see the first part of above item), A and B.
    The target points A and B must be selected/marked, with the selector button activated, then them user must "click" the secondary button to create segments .