Forms9Patch

A suite of elements built to simplify image management, text formatting, PNG generation, PDF generation, and printing for your NetStandard, PCL, and Shared Library Xamarin.Forms iOS, Android and UWP applications.

Overview

Xamarin Forms is great for developing cross platform applications (certainly very sane) but it is missing some important features:

• Patch scalable images
• SVG images
• Single point of use, cross platform, multi-screen / multi-resolution image management
• Simple, markup formatted text for labels and buttons
• Single point of use, cross platform, custom font management
• Segmented button control
• Pop-ups as a first class layout element
• Multi-object Clipboard and Inter-app Data Sharing
• PNG and PDF generation
• Printing

Android developers can use NinePatch bitmaps, the drawable directory naming convention, Html.FromHtml, and a bunch of complex file manipulations to address the image issue. Likewise, iOS developers can use ResizeableImageWithCapInsets, the @2x, @3x, @4x file naming convention, and some 3rd party libraries for this purpose. Custom fonts are a bit more complicated and label layouts take things up another notch. Forms9Patch enhances Xamarin Forms to make multi-resolution / multi-screen image management, custom fonts, and HTML text formatting easy for NetStandard, PCL and Shared Library applications for iOS, Android and UWP.

So, what exactly is Forms9Patch

Forms9Patch is a package of VisualElements plus a suite of Services, and Effects.

Visual Elements

Forms9Patch VisualElements is based upon three core elements from which five layouts, three buttons, and a number of pop-ups are built upon. The three core elements are:

• Forms9Patch.ImageSource: a free to use derivative of Xamarin.Forms.ImageSource to support multi-device / multi-density image management from Embedded Resources.
• Forms9Patch.Image: an enhanced implementation of Xamarin.Forms.Image with border (outline) and shadow properties plus support of SVG vector images. Raster images (.png, .jpg, .bmp) images also have patch scaling, tiling, and tinting support.
• Forms9Patch.Label: an enhanced implementation of Xamarin.Forms.Label for easy access to single-point-of-use custom fonts, auto-fitting, and text formatting via markup tags.

Forms9Patch's five layouts are derivatives of the five Xamarin.Forms.Layout subclasses - enhanced with the ability to use a Forms9Patch.Image as a background.

• Forms9Patch.Frame
• Forms9Patch.AbsoluteLayout
• Forms9Patch.Grid
• Forms9Patch.RelativeLayout
• Forms9Patch.StackLayout

Forms9Patch's three button elements (Forms9Patch.Button, Forms9Patch.StateButton, and Forms9Patch.SegmentedControl) are all derived from Xamarin.Forms.Button and share the following enhancements:

• A BackgroundImage property: Use a Forms9Patch.Image as a button background.
• An icon:
  • Specified either as markup text (IconText property) or as a Forms9Patch.Image (IconImage property). IconText makes it easy to use custom icon fonts like Material Icons. IconImage makes it easy to tint raster images or use SVG vector images.
  • A button's icon can be before (default) or after (TrailingIcon property true) its text and at the edge of the button (default) or next to the button's text (TightSpacing property true).
  • A button's icon or text can be arranged horizontally (default) or vertically (Orientation property set to StackOrientation.Vertical).
• A label:
  • Specified either as plain text (Text property) or markup text (HtmlText property).
  • Autofitting algorithms (see Autofitting )
• LongPressing and LongPressed touch events.

The three Forms9Patch button elements are:

• Forms9Patch.Button
• Forms9Patch.StateButton: a further enhanced implementation of Forms9Patch.Button that allow most enhanced properties to be configured by the button's state (Default, Pressing, Selected, Disabled, DisabledAndSelected)
• Forms9Patch.SegmentControl: a segmented button control that allows for border, separator, and shadow control. Note that there is currently no support for background images.

Forms9Patch's pop-up elements can be thought of as Forms9Patch layout elements (outline and background image capabilities) that renders with full page overlay backgrounds and the ability to be canceled by tapping the background. These popup elements are:

• Forms9Patch.ModalPopup: takes the enhancements (borders; patch-scalable, tintable, tile-able background images; shadows) from Forms9Patch.Frame and puts it into a pop-up layout.
• Forms9Patch.BubblePopup: goes a step further than Forms9Patch.ModalPopup by pointing to a target Xamarin.Forms.VisualElement. The pointer has PointerLength, PointerTipRadius and PointerCornerRadius properties.
• Forms9Patch.FlyoutPopup: a popup that "flies out" from a side of the display. Great for custom menus!
• Forms9Patch.ActivityIndicatorPopup: a convenience element that presents a Xamarin.Forms.ActivityIndicator over a page overlay.
• Forms9Patch.Toast: a convenience element that presents a title, a message and an optional confirmation button.
• Forms9Patch.PermissionPopup: a convenience element that presents a title, a message, and an accept and a decline button.
• Forms9Patch.TargetedToast: similar to Forms9Patch.Toast but enhanced to point to a Xamarin.Forms.VisualElement.
• Forms9Patch.TargetedMenu: A horizontal or vertical popup menu that can point to a VisualElement.

Services, and Effects

And lastly is Forms9Patch's services and effects:

• Keyboard Service: Want to put away the system keyboard? Want to be notified when the system keyboard appears or disappears?
• Keyboard Key Listener: What to know when a shortcut key is pressed? What about matching a shortcut key to a VisualElement so you only get the event when that VisualElement is in focus?
• Key Clicks Service: Do you want to make a system keyboard sound (and vibration, if available)?
• Application Info Service: Do you want to quickly know your application's Name, Bundle/Package ID, Build number and Version string?
• OS Info Service: What is the version of the device's operating system?
• Clipboard: Copy/paste text, HTML text, and multiple objects (they can be of the same or different MIME types) within your app or to other apps.
• Inter-app Data Sharing: Notice how some apps have a Share icon that presents a list of applications (and, on iOS services - like Print) to share data?
• ToPngService: Need a png of some HTML? How about the contents of a WebView?
• ToPdfService: Better yet, how about a PDF from some HTML or the content of a WebView?
• PrintService: Wait - how about printing some HTML or the content of a WebView?
• DiskSize: How much space is in your app's sandbox? How much is free? How much is used?
• EntryClearButtonEffect: want a clear button added to your Entry element?
• EmbeddedResourceFortEffect: use embedded resource fonts with Xamarin text elements;