feat(dialog): support minWidth, minHeight, maxWidth and maxHeight (#7488)

* feat(dialog): support minWidth, minHeight, maxWidth and maxHeight

* Adds Dialog support for `minWidth`, `minHeight`, `maxWidth` and `maxHeight` via config. Mostly delegates to Overlay.
* Moves declared `max-width` on `. mat-dialog-container` stylesheet to be authored via `MatDialogConfig`, providing the same default `80vw` value. Without this change, there would likely be undesired layout results due to different constraints being set on the overlay container vs the nested the dialog container.
* Added note on `minHeight` and `maxHeight` regarding the potential need to also set a `height` due to the rules around computed height resolution (https://www.w3.org/TR/CSS2/visudet.html#min-max-widths).  Any value set on `height` as a default would probably be assuming too much and may have varying results across browsers.

* test(dialog): add tests for minWidth, minHeight, maxWidth and maxHeight

* demo(dialog): add fields for minWidth, minHeight, maxWidth and maxHeight

Not adding `minWidth`, `minHeight`, `maxWidth` and `maxHeight` to `config` to avoid overriding the default value of `maxWidth` particularly—the type checker will require it to be a string. Instead, setting `config` to type `MatDialogConfig` is prefered to appease the type checker since those four properties are optional.

* demo(dialog): address AOT issues

Appeases the AOT type checker for the template by extending `MatDialogConfig` to disallow `position` from being undefined, given that it’s optional. Guards cannot be set on the template because the values are bound to NgModel.

* chore(dialog): address feedback regarding over-verbose comments

* fix(dialog): address feedback to not initialize some dialog config props

* demo(dialog): set init values for minWidth, minHeight, maxWidth and maxHeight

* chore(dialog): allow number|string for min/max widths and heights

src/demo-app/dialog/dialog-demo.html

@@ -23,6 +23,24 @@
       </mat-form-field>
     </p>
 
+    <p>
+      <mat-form-field>
+        <input matInput [(ngModel)]="config.minWidth" placeholder="Min Width">
+      </mat-form-field>
+      <mat-form-field>
+        <input matInput [(ngModel)]="config.minHeight" placeholder="Min Height">
+      </mat-form-field>
+    </p>
+
+    <p>
+      <mat-form-field>
+        <input matInput [(ngModel)]="config.maxWidth" placeholder="Max Width">
+      </mat-form-field>
+      <mat-form-field>
+        <input matInput [(ngModel)]="config.maxHeight" placeholder="Max Height">
+      </mat-form-field>
+    </p>
+
     <h2>Dialog position</h2>
 
     <p>

src/demo-app/dialog/dialog-demo.ts

@@ -1,7 +1,8 @@
 import {Component, Inject, ViewChild, TemplateRef} from '@angular/core';
 import {DOCUMENT} from '@angular/platform-browser';
-import {MatDialog, MatDialogRef, MAT_DIALOG_DATA} from '@angular/material';
+import {MatDialog, MatDialogConfig, MatDialogRef, MAT_DIALOG_DATA} from '@angular/material';
 
+const defaultDialogConfig = new MatDialogConfig();
 
 @Component({
   moduleId: module.id,
@@ -21,6 +22,10 @@ export class DialogDemo {
     backdropClass: '',
     width: '',
     height: '',
+    minWidth: '',
+    minHeight: '',
+    maxWidth: defaultDialogConfig.maxWidth,
+    maxHeight: '',
     position: {
       top: '',
       bottom: '',

src/lib/dialog/dialog-config.ts

@@ -57,6 +57,18 @@ export class MatDialogConfig {
   /** Height of the dialog. */
   height?: string = '';
 
+  /** Min-width of the dialog. If a number is provided, pixel units are assumed. */
+  minWidth?: number | string;
+
+  /** Min-height of the dialog. If a number is provided, pixel units are assumed. */
+  minHeight?: number | string;
+
+  /** Max-width of the dialog. If a number is provided, pixel units are assumed. Defaults to 80vw */
+  maxWidth?: number | string = '80vw';
+
+  /** Max-height of the dialog. If a number is provided, pixel units are assumed. */
+  maxHeight?: number | string;
+
   /** Position overrides. */
   position?: DialogPosition;
 

src/lib/dialog/dialog.scss

@@ -5,7 +5,6 @@
 
 $mat-dialog-padding: 24px !default;
 $mat-dialog-border-radius: 2px !default;
-$mat-dialog-max-width: 80vw !default;
 $mat-dialog-max-height: 65vh !default;
 $mat-dialog-button-margin: 8px !default;
 
@@ -17,7 +16,6 @@ $mat-dialog-button-margin: 8px !default;
   border-radius: $mat-dialog-border-radius;
   box-sizing: border-box;
   overflow: auto;
-  max-width: $mat-dialog-max-width;
   outline: 0;
 
   // The dialog container should completely fill its parent overlay element.

src/lib/dialog/dialog.spec.ts

@@ -336,6 +336,69 @@ describe('MatDialog', () => {
     expect(overlayPane.style.height).toBe('100px');
   });
 
+  it('should should override the min-width of the overlay pane', () => {
+    dialog.open(PizzaMsg, {
+      minWidth: '500px'
+    });
+
+    viewContainerFixture.detectChanges();
+
+    let overlayPane = overlayContainerElement.querySelector('.cdk-overlay-pane') as HTMLElement;
+
+    expect(overlayPane.style.minWidth).toBe('500px');
+  });
+
+  it('should should override the max-width of the overlay pane', fakeAsync(() => {
+    let dialogRef = dialog.open(PizzaMsg);
+
+    viewContainerFixture.detectChanges();
+
+    let overlayPane = overlayContainerElement.querySelector('.cdk-overlay-pane') as HTMLElement;
+
+    expect(overlayPane.style.maxWidth).toBe('80vw',
+      'Expected dialog to set a default max-width on overlay pane');
+
+    dialogRef.close();
+
+    tick(500);
+    viewContainerFixture.detectChanges();
+    flushMicrotasks();
+
+    dialogRef = dialog.open(PizzaMsg, {
+      maxWidth: '100px'
+    });
+
+    viewContainerFixture.detectChanges();
+
+    overlayPane = overlayContainerElement.querySelector('.cdk-overlay-pane') as HTMLElement;
+
+    expect(overlayPane.style.maxWidth).toBe('100px');
+  }));
+
+  it('should should override the min-height of the overlay pane', () => {
+    dialog.open(PizzaMsg, {
+      minHeight: '300px'
+    });
+
+    viewContainerFixture.detectChanges();
+
+    let overlayPane = overlayContainerElement.querySelector('.cdk-overlay-pane') as HTMLElement;
+
+    expect(overlayPane.style.minHeight).toBe('300px');
+  });
+
+  it('should should override the max-height of the overlay pane', () => {
+    dialog.open(PizzaMsg, {
+      maxHeight: '100px'
+    });
+
+    viewContainerFixture.detectChanges();
+
+    let overlayPane = overlayContainerElement.querySelector('.cdk-overlay-pane') as HTMLElement;
+
+    expect(overlayPane.style.maxHeight).toBe('100px');
+  });
+
   it('should should override the top offset of the overlay pane', () => {
     dialog.open(PizzaMsg, {
       position: {

src/lib/dialog/dialog.ts

@@ -190,7 +190,11 @@ export class MatDialog {
       scrollStrategy: this._scrollStrategy(),
       panelClass: dialogConfig.panelClass,
       hasBackdrop: dialogConfig.hasBackdrop,
-      direction: dialogConfig.direction
+      direction: dialogConfig.direction,
+      minWidth: dialogConfig.minWidth,
+      minHeight: dialogConfig.minHeight,
+      maxWidth: dialogConfig.maxWidth,
+      maxHeight: dialogConfig.maxHeight
     });
 
     if (dialogConfig.backdropClass) {