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66b93d5cfd
This change fixes the barnowl scrolling so that the ratios of 1/5, 1/2, and 2/3 are all relative to the visible viewport. The core part of the fix is that we need to call ui.message_viewport_info() to get the correct offsets for the top/height of the actually visible viewport Because this function is fairly expensive, I didn't want the helper functions needlessly re-calling it. I could have passed the helper functions the structure, but at that point it was simpler to inline their functionality. (imported from commit fb10d99313d568e85acfa70703c4651466acbc21)
114 lines
3.0 KiB
JavaScript
114 lines
3.0 KiB
JavaScript
var viewport = (function () {
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var exports = {};
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var jwindow;
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var height;
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var width;
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var in_stoppable_autoscroll = false;
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exports.at_top = function () {
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return (jwindow.scrollTop() <= 0);
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};
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exports.at_bottom = function () {
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// outerHeight(true): Include margin
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var bottom = jwindow.scrollTop() + jwindow.height();
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var window_size = $(document).height();
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// We only know within a pixel or two if we're
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// exactly at the bottom, due to browser quirkiness,
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// and we err on the side of saying that we are at
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// the bottom.
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return bottom + 2 >= window_size;
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};
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exports.set_message_position = function (message_top, viewport_info, ratio) {
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// message_top = offset of the top of a message that you are positioning
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// viewport_info = result of calling ui.message_viewport_info
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// ratio = fraction indicating how far down the screen the msg should be
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var hidden_top =
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viewport_info.visible_top
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- jwindow.scrollTop();
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var message_offset =
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viewport_info.visible_height * ratio
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+ hidden_top;
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var new_scroll_top =
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message_top
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- message_offset;
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jwindow.scrollTop(new_scroll_top);
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};
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exports.scrollTop = function viewport_scrollTop () {
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return jwindow.scrollTop.apply(jwindow, arguments);
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};
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exports.height = function viewport_height() {
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if (arguments.length !== 0) {
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height = undefined;
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return jwindow.height.apply(jwindow, arguments);
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}
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if (height === undefined) {
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height = $(window).height();
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}
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return height;
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};
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exports.width = function viewport_width() {
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if (arguments.length !== 0) {
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width = undefined;
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return jwindow.width.apply(jwindow, arguments);
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}
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if (width === undefined) {
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width = jwindow.width();
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}
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return width;
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};
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exports.stop_auto_scrolling = function() {
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if (in_stoppable_autoscroll) {
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$("html, body").stop();
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}
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};
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exports.system_initiated_animate_scroll = function (scroll_amount) {
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suppress_scroll_pointer_update = true; // Gets set to false in the scroll handler.
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var viewport_offset = exports.scrollTop();
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in_stoppable_autoscroll = true;
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$("html, body").animate({
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scrollTop: viewport_offset + scroll_amount,
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always: function () {
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in_stoppable_autoscroll = false;
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}
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});
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};
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exports.user_initiated_animate_scroll = function (scroll_amount) {
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suppress_scroll_pointer_update = true; // Gets set to false in the scroll handler.
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in_stoppable_autoscroll = false; // defensive
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var viewport_offset = exports.scrollTop();
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// We use $('html, body') because you can't animate window.scrollTop
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// on Chrome (http://bugs.jquery.com/ticket/10419).
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$("html, body").animate({
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scrollTop: viewport_offset + scroll_amount
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});
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};
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$(function () {
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jwindow = $(window);
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// This handler must be placed before all resize handlers in our application
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jwindow.resize(function () {
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height = undefined;
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width = undefined;
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});
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});
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return exports;
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}());
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