Fading Toolbar on scrolling of a tab (in Codename One)


How to fade the Toolbar on scrolling is described in the Codename One manual, in the section "Title Animations": https://www.codenameone.com/manual/components.html#title-animations-section

The example code (taken from the given link) works. I slightly modified it because I need to fade the Toolbar on scrolling of tabs, but my code doesn't work. Can you help me to fix it? Please try to scroll the "Tab 3" (that is the only scrollable), I tested with iPhone skin in the Codename One Simulator. Thank you

    Form hi = new Form("Toolbar", new BorderLayout());
    EncodedImage placeholder = EncodedImage.createFromImage(Image.createImage(hi.getWidth(), hi.getWidth() / 5, 0xffff0000), true);
    URLImage background = URLImage.createToStorage(placeholder, "400px-AGameOfThrones.jpg",
    Style stitle = hi.getToolbar().getTitleComponent().getUnselectedStyle();
    stitle.setPaddingUnit(Style.UNIT_TYPE_DIPS, Style.UNIT_TYPE_DIPS, Style.UNIT_TYPE_DIPS, Style.UNIT_TYPE_DIPS);
    SpanButton credit = new SpanButton("This excerpt is from A Wiki Of Ice And Fire. Please check it out by clicking here!");
    credit.addActionListener((e) -> Display.getInstance().execute("http://awoiaf.westeros.org/index.php/A_Game_of_Thrones"));

    Tabs tabs = new Tabs();
    Container cnt3 = BoxLayout.encloseY(new SpanLabel("A Game of Thrones is set in the Seven Kingdoms of Westeros, a land reminiscent of Medieval Europe. In Westeros the seasons last for years, sometimes decades, at a time.\n\nFifteen years prior to the novel, the Seven Kingdoms were torn apart by a civil war, known alternately as \"Robert's Rebellion\" and the \"War of the Usurper.\" Prince Rhaegar Targaryen kidnapped Lyanna Stark, arousing the ire of her family and of her betrothed, Lord Robert Baratheon (the war's titular rebel). The Mad King, Aerys II Targaryen, had Lyanna's father and eldest brother executed when they demanded her safe return. Her second brother, Eddard, joined his boyhood friend Robert Baratheon and Jon Arryn, with whom they had been fostered as children, in declaring war against the ruling Targaryen dynasty, securing the allegiances of House Tully and House Arryn through a network of dynastic marriages (Lord Eddard to Catelyn Tully and Lord Arryn to Lysa Tully). The powerful House Tyrell continued to support the King, but House Lannister and House Martell both stalled due to insults against their houses by the Targaryens. The civil war climaxed with the Battle of the Trident, when Prince Rhaegar was killed in battle by Robert Baratheon. The Lannisters finally agreed to support King Aerys, but then brutally... "));
    tabs.addTab("Tab 1", new SpanLabel("A Game of Thrones is the first of seven planned novels in A Song of Ice and Fire, an epic fantasy series by American author George R. R. Martin. It was first published on 6 August 1996. The novel was nominated for the 1998 Nebula Award and the 1997 World Fantasy Award,[1] and won the 1997 Locus Award.[2] The novella Blood of the Dragon, comprising the Daenerys Targaryen chapters from the novel, won the 1997 Hugo Award for Best Novella. "));
    tabs.addTab("Tab 2", new Label("Plot introduction", "Heading"));
    tabs.addTab("Tab 3", cnt3);

    hi.add(BorderLayout.CENTER, tabs);

    ComponentAnimation title = hi.getToolbar().getTitleComponent().createStyleAnimation("Title", 200);

1 Answer


After better reading the Javadocs, I found this possible solution:

ComponentAnimation title = hi.getToolbar().getTitleComponent().createStyleAnimation("Title", 200);
        for (int i = 0; i < tabs.getTabCount(); i++) {
            Component tab = tabs.getTabComponentAt(i);
            if (tab instanceof Container) {
                hi.getAnimationManager().onTitleScrollAnimation((Container)tab, title);
answered on Stack Overflow Apr 25, 2019 by Francesco Galgani

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