Re: How to make my java applets more user friendly

From:
=?ISO-8859-1?Q?Arne_Vajh=F8j?= <arne@vajhoej.dk>
Newsgroups:
comp.lang.java.programmer
Date:
Sun, 13 Jul 2014 10:55:44 -0400
Message-ID:
<53c29df0$0$301$14726298@news.sunsite.dk>
On 7/13/2014 10:49 AM, Arne Vajh?j wrote:

On 7/13/2014 6:15 AM, Tom Adams wrote:

On Sunday, July 6, 2014 12:26:27 PM UTC-4, Arne Vajh?j wrote:

On 7/4/2014 5:55 AM, Tom Adams wrote:

I recently started looking at GWT. I find mixed info on whether it

will compile an applet (the UI classes I guess?),


It won't.

You write a GUI application in Java. GWT translates it to JavaScript
and it runs in any browser with no requirement for Java.


I am confused by this. Perhaps it's the terminology. You say it
won't "compile" and applet, but it will "translate" an applet.

When I said compile, I meant compile where the target "machine code"
was javascript. That's the same a translate, right?


Yes.

GWT does compile/translate to JavaScript.

But it does not compile/translate applets.

It compiles/translates Java code written in its own GUI framework.

What I want to know is that if I go to the trouble of climbing the GWT
learning curve, will I just have to issue a command and end up with
some javascript that will do what the applet does without needing the
java plugin.


Users will not need Java installed.

Or, will I have to re-code a lot of the java code even if I am using
the GWT?


The code will need to be rewritten. But I think you will find all the
concepts very familiar!


Let me post a small example:

package test.client;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.Grid;
import com.google.gwt.user.client.ui.InlineLabel;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.ScrollPanel;
import com.google.gwt.user.client.ui.TabPanel;
import com.google.gwt.user.client.ui.RichTextArea;
import com.google.gwt.user.client.ui.TextBox;

public class Page implements EntryPoint {
    public void onModuleLoad() {
        final TextBox tb1 = new TextBox();
        final TextBox tb2 = new TextBox();
        final TextBox tb3 = new TextBox();
        final Button addbtn = new Button("Add");
         addbtn.addClickHandler(new ClickHandler() {
          public void onClick(ClickEvent event) {
          int v1 = Integer.parseInt(tb1.getText());
          int v2 = Integer.parseInt(tb2.getText());
          int v3 = v1 + v2;
          tb3.setText(Integer.toString(v3));
          }
         });
         final Grid addgrd = new Grid(4, 2);
         addgrd.setWidget(0, 0, new InlineLabel("First number: "));
        addgrd.setWidget(0, 1, tb1);
         addgrd.setWidget(1, 0, new InlineLabel("Second number: "));
        addgrd.setWidget(1, 1, tb2);
         addgrd.setWidget(2, 0, new InlineLabel("Result number: "));
        addgrd.setWidget(2, 1, tb3);
        addgrd.setWidget(3, 0, addbtn);
        final RichTextArea rta = new RichTextArea();
        final Button bldbtn = new Button("B");
        bldbtn.addClickHandler(new ClickHandler() {
          public void onClick(ClickEvent event) {
          rta.getFormatter().toggleBold();
          }
         });
        final Button itbtn = new Button("I");
        itbtn.addClickHandler(new ClickHandler() {
          public void onClick(ClickEvent event) {
          rta.getFormatter().toggleItalic();
          }
         });
        final FlowPanel flowp = new FlowPanel();
        flowp.add(new ScrollPanel(rta));
         flowp.add(bldbtn);
         flowp.add(itbtn);
        final TabPanel tabp = new TabPanel();
        tabp.add(addgrd, "Add");
        tabp.add(flowp, "Edit");
        tabp.selectTab(0);
        RootPanel.get("content").add(tabp);
    }
}

Conceptually that is very close to a Swing app.

Arne

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