silverstripe-framework/admin/javascript/LeftAndMain.Layout.js
Hamish Friedlander 0ca4969cda FIX Dont update preview iframe if hidden
Updating the iframe src when the iframe isnt visible in IE8 causes a
view disconcerting font glitch (and it slows down navigation anyway),
so if the iframe isnt visible, delay setting the src until it is
2013-08-21 09:29:28 +12:00

174 lines
6.0 KiB
JavaScript

/**
* File: LeftAndMain.Layout.js
*/
(function($) {
$.fn.layout.defaults.resize = false;
/**
* Acccess the global variable in the same way the plugin does it.
*/
jLayout = (typeof jLayout === 'undefined') ? {} : jLayout;
/**
* Factory function for generating new type of algorithm for our CMS.
*
* Spec requires a definition of three column elements:
* - `menu` on the left
* - `content` area in the middle (includes the EditForm, side tool panel, actions, breadcrumbs and tabs)
* - `preview` on the right (will be shown if there is enough space)
*
* Required options:
* - `minContentWidth`: minimum size for the content display as long as the preview is visible
* - `minPreviewWidth`: preview will not be displayed below this size
* - `mode`: one of "split", "content" or "preview"
*
* The algorithm first checks which columns are to be visible and which hidden.
*
* In the case where both preview and content should be shown it first tries to assign half of non-menu space to
* preview and the other half to content. Then if there is not enough space for either content or preview, it tries
* to allocate the minimum acceptable space to that column, and the rest to the other one. If the minimum
* requirements are still not met, it falls back to showing content only.
*
* @param spec A structure defining columns and parameters as per above.
*/
jLayout.threeColumnCompressor = function (spec, options) {
// Spec sanity checks.
if (typeof spec.menu==='undefined' ||
typeof spec.content==='undefined' ||
typeof spec.preview==='undefined') {
throw 'Spec is invalid. Please provide "menu", "content" and "preview" elements.';
}
if (typeof options.minContentWidth==='undefined' ||
typeof options.minPreviewWidth==='undefined' ||
typeof options.mode==='undefined') {
throw 'Spec is invalid. Please provide "minContentWidth", "minPreviewWidth", "mode"';
}
if (options.mode!=='split' && options.mode!=='content' && options.mode!=='preview') {
throw 'Spec is invalid. "mode" should be either "split", "content" or "preview"';
}
// Instance of the algorithm being produced.
var obj = {
options: options
};
// Internal column handles, also implementing layout.
var menu = $.jLayoutWrap(spec.menu),
content = $.jLayoutWrap(spec.content),
preview = $.jLayoutWrap(spec.preview);
/**
* Required interface implementations follow.
* Refer to https://github.com/bramstein/jlayout#layout-algorithms for the interface spec.
*/
obj.layout = function (container) {
var size = container.bounds(),
insets = container.insets(),
top = insets.top,
bottom = size.height - insets.bottom,
left = insets.left,
right = size.width - insets.right;
var menuWidth = spec.menu.width(),
contentWidth = 0,
previewWidth = 0;
if (this.options.mode==='preview') {
// All non-menu space allocated to preview.
contentWidth = 0;
previewWidth = right - left - menuWidth;
} else if (this.options.mode==='content') {
// All non-menu space allocated to content.
contentWidth = right - left - menuWidth;
previewWidth = 0;
} else { // ==='split'
// Split view - first try 50-50 distribution.
contentWidth = (right - left - menuWidth) / 2;
previewWidth = right - left - (menuWidth + contentWidth);
// If violating one of the minima, try to readjust towards satisfying it.
if (contentWidth < this.options.minContentWidth) {
contentWidth = this.options.minContentWidth;
previewWidth = right - left - (menuWidth + contentWidth);
} else if (previewWidth < this.options.minPreviewWidth) {
previewWidth = this.options.minPreviewWidth;
contentWidth = right - left - (menuWidth + previewWidth);
}
// If still violating one of the (other) minima, remove the preview and allocate everything to content.
if (contentWidth < this.options.minContentWidth || previewWidth < this.options.minPreviewWidth) {
contentWidth = right - left - menuWidth;
previewWidth = 0;
}
}
// Calculate what columns are already hidden pre-layout
var prehidden = {
content: spec.content.hasClass('column-hidden'),
preview: spec.preview.hasClass('column-hidden')
};
// Calculate what columns will be hidden (zero width) post-layout
var posthidden = {
content: contentWidth === 0,
preview: previewWidth === 0
};
// Apply classes for elements that might not be visible at all.
spec.content.toggleClass('column-hidden', posthidden.content);
spec.preview.toggleClass('column-hidden', posthidden.preview);
// Apply the widths to columns, and call subordinate layouts to arrange the children.
menu.bounds({'x': left, 'y': top, 'height': bottom - top, 'width': menuWidth});
menu.doLayout();
left += menuWidth;
content.bounds({'x': left, 'y': top, 'height': bottom - top, 'width': contentWidth});
if (!posthidden.content) content.doLayout();
left += contentWidth;
preview.bounds({'x': left, 'y': top, 'height': bottom - top, 'width': previewWidth});
if (!posthidden.preview) preview.doLayout();
if (posthidden.content !== prehidden.content) spec.content.trigger('columnvisibilitychanged');
if (posthidden.preview !== prehidden.preview) spec.preview.trigger('columnvisibilitychanged');
return container;
};
/**
* Helper to generate the required `preferred`, `minimum` and `maximum` interface functions.
*/
function typeLayout(type) {
var func = type + 'Size';
return function (container) {
var menuSize = menu[func](),
contentSize = content[func](),
previewSize = preview[func](),
insets = container.insets();
width = menuSize.width + contentSize.width + previewSize.width;
height = Math.max(menuSize.height, contentSize.height, previewSize.height);
return {
'width': insets.left + insets.right + width,
'height': insets.top + insets.bottom + height
};
};
}
// Generate interface functions.
obj.preferred = typeLayout('preferred');
obj.minimum = typeLayout('minimum');
obj.maximum = typeLayout('maximum');
return obj;
};
}(jQuery));