Rather than require Sky developers to have a Python environment, we should
write our tooling for Sky in Dart. This CL converts skyx.py into skyx.dart and
makes skyx.py into a wrapper for skyx.dart. We still need the Python wrapper
because gn requires that build actions are written in Python.

This code isn't wired into the main build yet. We'll need to add some more pub
packages to our buildbot environment first.

TBR=eseidel@google.com

Review URL: https://codereview.chromium.org/1213213003.

TBR=ianh@google.com,mpcomplete@google.com

Review URL: https://codereview.chromium.org/1213573006.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1212013004.

TBR=ianh@google.com

Review URL: https://codereview.chromium.org/1221023002.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1216923008.

Refactors clamp function

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1215413002.

Currently this asset bundle is based on the network, but soon we'll be able to
use a local asset bundle.

R=jackson@google.com

Review URL: https://codereview.chromium.org/1217593004.

Previously, RenderImage knew about image_cache and expected to work in terms of
URLs. Now RenderImage works directly with sky.Image and it's the job of the
widgets system to interact with the network cache.

At the widgets layer, I've factored this work into three parts:
1) A wrapper for RenderImage that works in terms of sky.Image.
2) A component that can deal with any sort of Future<sky.Image>.
3) A NetworkImage component that translates relative URLs into
   Future<sky.Image> using the image_cache.

A future CL will add a peer to NetworkImage that gets Future<sky.Image>s from
an asset bundle.

R=ianh@google.com, jackson@google.com

Review URL: https://codereview.chromium.org/1218023013.

This introduces an AnimationPerformance class, which is intended to manage an
animation (or its reverse), with the ability to manually control the timeline
or to apply a force to advance the animation with a diminishing speed.

I'm having trouble fitting the odeon model to Sky. Odeon has a lot of nice
properties, but fundamentally operates on UINodes, which contain all the
properties to be animated. Sky, on the other hand, has no such universal
properties. Instead, each Widget assembles itself how it sees fit.

So my current plan is to let AnimationPerformance own a generic set of
AnimatedVariables. You pass it a bag of things, say position and opacity, as
AnimatedVariables. It updates them based on the animation, and they each have
a way to build a widget based on their current state.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1211603003.

I didn't exactly follow the android API, but pretty close.

Also started a java/common implementation for things like
DataPipeUtils. I only needed the ability to copy from a data
pipe to a file, so that's the only function we have so far.

Fixes https://github.com/domokit/mojo/issues/270

R=abarth@chromium.org, abarth@google.com

Review URL: https://codereview.chromium.org/1211913005.

This entails:
 - Making the baseline logic cache results.
 - Making the baseline logic track who used its information.
 - Making the baseline logic mark all ancestors up to whoever used
   its information wheneven its node gets markNeedsLayout.
 - Making RenderShrinkWrapWidth make its child respect the step width
   and step height, rather than just sizing the child then snapping.
   This is required to make the ink splashes render right on menus
   that are snapped.
 - Adding debugDescribeSettings() to RenderShrinkWrapWidth.
 - Introducing a RenderBaseline class that offsets its child to a
   certain baseline.
 - Factoring out some common code from RenderBaseline and
   RenderPositionedBox to RenderShiftedBox.
 - Redoing all the menu layout logic.

BUG=
R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1219113003.

Future<sky.Image> is easier to work with than a callback that provides an
image. It will also let us use other images sources that vend futures to
images.

R=jackson@google.com

Review URL: https://codereview.chromium.org/1216303005.

Also, remove the non-SkyView client of DartController to simplify the code
further.

R=chinmaygarde@google.com

Review URL: https://codereview.chromium.org/1210253005.

R=eseidel@chromium.org, eseidel@google.com

Review URL: https://codereview.chromium.org/1217083009.

This code existed to service WebView, which no longer exists.

R=eseidel@chromium.org, eseidel@google.com

Review URL: https://codereview.chromium.org/1209033016.

These dependencies will trigger a "gn check" violation in a future version of
gn.

TBR=eseidel@google.com

Review URL: https://codereview.chromium.org/1218173003.

This CL also removes the HTML parser and the HTML import system.

TBR=eseidel@google.com

Review URL: https://codereview.chromium.org/1215103007.

This layer is no longer needed now that the new world is gone.

TBR=eseidel@google.com

Review URL: https://codereview.chromium.org/1210153009.

Changed FixedHeightScrollable so that if the list shrinks past the current scrollOffset, the scrollOffset is adjusted so that the last/only page of the list remains visible.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1216323002.

Previously we defaulted to main.dart, which was confusing. Now we default to
the current working directory, which is more understandable. As part of this
change, I've also changed the default location of main.dart to lib/main.dart,
which makes our current examples.

Fixes #274

R=eseidel@chromium.org, eseidel@google.com

Review URL: https://codereview.chromium.org/1215103006.

Fixes #275

R=eseidel@chromium.org, eseidel@google.com

Review URL: https://codereview.chromium.org/1216283003.

dartanalyzer

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1215883006.

BUG=
R=abarth@chromium.org, chinmaygarde@google.com, ianh@google.com

Review URL: https://codereview.chromium.org/1219953002.

Please use ".dart" files instead.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1222483002.

BUG=
R=abarth@chromium.org, ianh@google.com

Review URL: https://codereview.chromium.org/1221893002.

Note that this wildly breaks the vertical alignment of menu items, I'll fix that in a subsequent CL.
(It wasn't really working before either, but looked ok by pure luck.)

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1215613005.

These tests now run in the DOM-less world.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1212163009.

TBR=abarth

Review URL: https://codereview.chromium.org/1214413002.

Demo all three varieties of TabLabels in 3 different
TabNavigators. Use another TabNavigator to select
among the three Card-encapsulated demos.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1217243005.

Remove Material's opinion about background colours, since in fact the background colour varies dramatically with the kind of material involved.

Also:
- give users of Material who previously relied on Material's defaults
  opinions about background colours
- reindent stock_row.dart
- import colors as colors in example/widgets/styled_text.dart, rather
  than in global scope, for consistency with other files
- import typography as typograpyh in example/widgets/tabs.dart, rather
  than in global scope, for consistency with other files
- make flat_button actually be transparent by not painting a
  background, rather than painting 0x00000000. This is the what I
  actually originally set out to do here.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1217293003.

These tests are for aspects of the Sky engine we plan to remove along with
support for the old world.

R=ianh@google.com

Review URL: https://codereview.chromium.org/1215063003.

TBR=ianh@google.com

Review URL: https://codereview.chromium.org/1218903004.

I ran this and fixed some of the warnings flagged:
cd ~/dev/mojo/src/sky && find engine/core/painting sdk/example sdk/lib -type f -name '*.dart' | perl -nE 'chomp; local $/ = undef; open(FILE, $_); my $file = <FILE>; print $file; next if $file =~ /^part of/om; say "import \"$_\";"' > all.dart && shelldb analyze all.dart 2>&1 | grep -v 'sky/all.dart'

Then I loaded the affected examples and fixed any bugs I found from running them.

Major change to SDK:

- Fix RenderPadding to get a valid size when it has no child (it was
  previously sizing itself too small by the padding amount).

Minor changes, mostly to examples:

- Fix the 'part of' lines in sky_shell_dart_controller_service_isolate
  to match the library name given in main.dart.

- Remove unused imports in various places.

- Fix example/game/lib/texture.dart to use the new Rect creation APIs.

- Remove unused code in example/mine_digger/lib/main.dart.

- Fix example/raw/hello_world.dart to use the new Size.center API.

- Fix example/rendering/baseline.dart and
  example/rendering/justify_content.dart to have readable text.

- Fix compile error in example/rendering/transform.dart.

- Extend the debugDoesMeetConstraints() method to print useful
  information when it will be used to fire an assert.

- Remove a warning about abstract methods on RenderView that would for
  some reason only sometimes get flagged by the analyzer.

R=abarth@chromium.org, jackson@google.com

Review URL: https://codereview.chromium.org/1215163003.

Please use package:sky/widgets instead.

R=ianh@google.com, eseidel@google.com

Review URL: https://codereview.chromium.org/1221883002.

One of the build bots is missing the yaml package. Reverting until we sort out
how to fix that bot.

TBR=jackson@google.com

Review URL: https://codereview.chromium.org/1217863003.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1217573003.

This CL teaches the build system how to create the stocks.skyx application
bundle. This bundle contains the stocks snapshot as well as the material design
assets needed by the stocks app to run offline.

R=eseidel@chromium.org, eseidel@google.com

Review URL: https://codereview.chromium.org/1216273002.

We need the material design icons at build time in order to build Sky
application bundles that include the icons. Therefore, we need can't wait until
runtime to download the icons.

Also, rather than copying all the icons into each out directory, we just
symlink to the copy in the source tree.

R=eseidel@chromium.org, eseidel@google.com

Review URL: https://codereview.chromium.org/1217283002.

This script consumes a sky.yaml file and produces a bundle that contains the
listed material design assets as well as the snapshot binary. This script isn't
wired into the build system yet because we don't yet download the material
design icons using DEPS.

R=chinmaygarde@google.com, eseidel@google.com

Review URL: https://codereview.chromium.org/1220893002.

Adds color sequence class
Refactors drawing of textures

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1216573009.