/* gallery.js ------------------------------------------------------------------------------------- Copyright Christopher Fulham Email: christopher@christopherfulham.com Based on web programming by Tim Brook Purpose ~~~~~~~ Provide gallery behaviour for Christopher.com.au - uses data from christopherData.js or similar file ** Notes ** ~~~~~~~~~~~ Calling HTML page must have: or

element with id=ground

element with id=bigScreen element with id=screen element with id=workTitle (It may also have a

with id=navDisplay if it includes navigation buttons.) Calling HTML page must load windows.js and pix.js before this file and data.js after -----------------------------------------------------------------------------------*/ // Constants // ~~~~~~~~~ PIX = 1000 ; // Max No. of pix in data.js (inc. No.0) without recoding functions // variable declared in pix.js // not formally constant because may be reset in data.js var W = screen.availWidth - 20 ; // Effective available pixels in big window var H = screen.availHeight - 100 ; // (again not technically constants because may be reset on HTML page) // Global variables // ~~~~~~~~~~~~~~~~ var marginB = 30 + 0.1 * H ; // Pixel margin under pic to allow for navigation buttons // value may be overridden in data.js var pic = new Array(PIX) ; // The array of slides var picNo = 0 ; // The No. of the slide (pic) currently showing - // updated by showSlide() in this file and docDraw() in drawing.js // it may be (re)initialised on the HTML page; // ------------------------------------------ // Object types // ~~~~~~~~~~~~ // An image in a slide show ---------------- function Slide() { this.title = 'untitled' ; this.year = '' ; this.file = 'loading.jpg' ; // Filename for pic this.width = 640 ; // Pixel width of pic in the file this.height = 360 ; // Pixel height of pic in file this.matt = '#000' ; // Suitable background colour to surround the pic this.time = 3 ; // No. of seconds to display the pic on screen this.next = NaN ; // Successor (next pic) this.blurb = document.createElement('SPAN') ; // Short text to accompany pic this.blurb.appendChild(document.createTextNode('')) ; } // ---------------------------------------- // ------------------------------------------ // Initialisation // ~~~~~~~~~~~~~~ for (var i = 0; i < PIX; i++) { pic[i] = new Slide ; // pic[i] fields redefined in the data.js file for the page // successors often redefined on the HTML page to make a specific show if (i+1 < PIX) pic[i].next = i+1 ; } pic[0].file = 'loading.png' ; pic[0].title = 'Loading...' ; pic[0].time = 1 ; // Only short delay while pic No.0 ('Loading...') displays //-------------------------------------------------------------------------------- // Main functions // ~~~~~~~~~~~~~~ // Return the successor of an integer - // coded as a function for consistency with pred() and to allow for out-of -range arguments function succ(n) { return n < 0 ? 1 : n < PIX ? Math.max(1, pic[n].next) : NaN } // Return the predecessor of an integer n (the No. of the pic preceding pic[n]) // [If there is more than 1 predecessor, return the last // unless pic[n] is it's own successor, in which case return n itself; // If there is no predecessor, return NaN. ] function pred(n) { var p = NaN ; // the predecessor for (var i = 0 ; i < PIX ; i++) { if (pic[i].next == n) p = i } return (pic[n].next == n) ? n : p } // --------------------------------------- // Show pic number n with title. blurb etc, and update picNo variable function showPic(n) { // remember which pic is showing picNo = n ; with (document) { // Show pic centred getElementById('screen').src = "../jpeg/" + pic[n].file ; /* getElementById('bigScreen').style.marginLeft = (-pic[n].width / 2) + 'px' ; */ // Show title title = pic[n].title; getElementById('screen').alt = title ; getElementById('screen').title = pic[n].title ; getElementById('title').innerHTML = pic[n].title ; getElementById('caption').innerHTML = pic[n].year + pic[n].blurb ; } }